Merge remote-tracking branch 'origin/master' into ptr_as_ptr

.github/workflows/main.yml

@@ -50,12 +50,12 @@ jobs:
       - run: cargo test --features bundled --workspace --all-targets --verbose
       - run: cargo test --features bundled --workspace --doc --verbose
 
-      - name: Test Features
+      - name: Add llvm path on Windows
-        # TODO: clang is installed on these -- but `bindgen` can't find it...
+        if: matrix.os == 'windows-latest'
-        if: matrix.os != 'windows-latest'
+        run: echo "C:\msys64\mingw64\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
-        run: |
+
-          cargo test --features 'bundled-full session buildtime_bindgen' --all-targets --workspace --verbose
+      - run: cargo test --features 'bundled-full session buildtime_bindgen' --all-targets --workspace --verbose
-          cargo test --features 'bundled-full session buildtime_bindgen' --doc --workspace --verbose
+      - run: cargo test --features 'bundled-full session buildtime_bindgen' --doc --workspace --verbose
 
       # TODO: move into own action for better caching
       - name: Static build
@@ -97,11 +97,12 @@ jobs:
       - run: cargo test --features 'modern-full bundled-sqlcipher-vendored-openssl' --all-targets --workspace --verbose
       - run: cargo test --features 'modern-full bundled-sqlcipher-vendored-openssl' --doc --workspace --verbose
 
-      - name: Test Features
+      - name: Add llvm path on Windows
-        if: matrix.os != 'windows-latest'
+        if: matrix.os == 'windows-latest'
-        run: |
+        run: echo "C:\msys64\mingw64\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
-          cargo test --features 'bundled-full session buildtime_bindgen' --all-targets --workspace --verbose
+
-          cargo test --features 'bundled-full session buildtime_bindgen' --doc --workspace --verbose
+      - run: cargo test --features 'bundled-full session buildtime_bindgen' --all-targets --workspace --verbose
+      - run: cargo test --features 'bundled-full session buildtime_bindgen' --doc --workspace --verbose
 
   winsqlite3:
     name: Test with winsqlite3

README.md

@@ -1,13 +1,12 @@
 # Rusqlite
 
-[![Travis Build Status](https://api.travis-ci.org/rusqlite/rusqlite.svg?branch=master)](https://travis-ci.org/rusqlite/rusqlite)
-[![AppVeyor Build Status](https://ci.appveyor.com/api/projects/status/github/rusqlite/rusqlite?branch=master&svg=true)](https://ci.appveyor.com/project/rusqlite/rusqlite)
-[![Build Status](https://github.com/rusqlite/rusqlite/workflows/CI/badge.svg)](https://github.com/rusqlite/rusqlite/actions)
-[![dependency status](https://deps.rs/repo/github/rusqlite/rusqlite/status.svg)](https://deps.rs/repo/github/rusqlite/rusqlite)
 [![Latest Version](https://img.shields.io/crates/v/rusqlite.svg)](https://crates.io/crates/rusqlite)
-[![Gitter](https://badges.gitter.im/rusqlite.svg)](https://gitter.im/rusqlite/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
+[![Documentation](https://docs.rs/rusqlite/badge.svg)](https://docs.rs/rusqlite)
-[![Docs](https://docs.rs/rusqlite/badge.svg)](https://docs.rs/rusqlite)
+[![Build Status (GitHub)](https://github.com/rusqlite/rusqlite/workflows/CI/badge.svg)](https://github.com/rusqlite/rusqlite/actions)
-[![codecov](https://codecov.io/gh/rusqlite/rusqlite/branch/master/graph/badge.svg)](https://codecov.io/gh/rusqlite/rusqlite)
+[![Build Status (AppVeyor)](https://ci.appveyor.com/api/projects/status/github/rusqlite/rusqlite?branch=master&svg=true)](https://ci.appveyor.com/project/rusqlite/rusqlite)
+[![Code Coverage](https://codecov.io/gh/rusqlite/rusqlite/branch/master/graph/badge.svg)](https://codecov.io/gh/rusqlite/rusqlite)
+[![Dependency Status](https://deps.rs/repo/github/rusqlite/rusqlite/status.svg)](https://deps.rs/repo/github/rusqlite/rusqlite)
+[![Discord Chat](https://img.shields.io/discord/927966344266256434.svg?logo=discord)](https://discord.gg/G6Se6Yzw)
 
 Rusqlite is an ergonomic wrapper for using SQLite from Rust. It attempts to expose
 an interface similar to [rust-postgres](https://github.com/sfackler/rust-postgres).
@@ -212,7 +211,7 @@ here: https://github.com/rusqlite/rusqlite/graphs/contributors
 
 ## Community
 
-Currently there's a gitter channel set up for rusqlite [here](https://gitter.im/rusqlite/community).
+Feel free to join the [Rusqlite Discord Server](https://discord.gg/G6Se6Yzw) to discuss or get help with `rusqlite` or `libsqlite3-sys`.
 
 ## License
 

libsqlite3-sys/build.rs

@@ -46,9 +46,9 @@ fn main() {
                 features 'bundled' and 'bundled-windows'. If you want a bundled build of
                 SQLCipher (available for the moment only on Unix), use feature 'bundled-sqlcipher'
                 or 'bundled-sqlcipher-vendored-openssl' to also bundle OpenSSL crypto."
-            )
+            );
         }
-        build_linked::main(&out_dir, &out_path)
+        build_linked::main(&out_dir, &out_path);
     } else if cfg!(feature = "bundled")
         || (win_target() && cfg!(feature = "bundled-windows"))
         || cfg!(feature = "bundled-sqlcipher")
@@ -66,7 +66,7 @@ fn main() {
         )))]
         panic!("The runtime test should not run this branch, which has not compiled any logic.")
     } else {
-        build_linked::main(&out_dir, &out_path)
+        build_linked::main(&out_dir, &out_path);
     }
 }
 
@@ -168,7 +168,7 @@ mod build_bundled {
                             panic!(
                                 "OpenSSL include directory does not exist: {}",
                                 inc_dir.to_string_lossy()
-                            )
+                            );
                         }
 
                         use_openssl = true;
@@ -429,19 +429,17 @@ mod build_linked {
         }
 
         // See if pkg-config can do everything for us.
-        match pkg_config::Config::new()
+        if let Ok(mut lib) = pkg_config::Config::new()
             .print_system_libs(false)
             .probe(link_lib)
         {
-            Ok(mut lib) => {
             if let Some(mut header) = lib.include_paths.pop() {
                 header.push("sqlite3.h");
                 HeaderLocation::FromPath(header.to_string_lossy().into())
             } else {
                 HeaderLocation::Wrapper
             }
-            }
+        } else {
-            Err(_) => {
             // No env var set and pkg-config couldn't help; just output the link-lib
             // request and hope that the library exists on the system paths. We used to
             // output /usr/lib explicitly, but that can introduce other linking problems;
@@ -450,7 +448,6 @@ mod build_linked {
             HeaderLocation::Wrapper
         }
     }
-    }
 
     fn try_vcpkg() -> Option<HeaderLocation> {
         if cfg!(feature = "vcpkg") && is_compiler("msvc") {

libsqlite3-sys/src/error.rs

@@ -63,6 +63,7 @@ pub struct Error {
 }
 
 impl Error {
+    #[must_use]
     pub fn new(result_code: c_int) -> Error {
         let code = match result_code & 0xff {
             super::SQLITE_INTERNAL => ErrorCode::InternalMalfunction,
@@ -192,6 +193,7 @@ const SQLITE_WARNING_AUTOINDEX: c_int = SQLITE_WARNING | (1 << 8);
 
 const SQLITE_AUTH_USER: c_int = super::SQLITE_AUTH | (1 << 8);
 
+#[must_use]
 pub fn code_to_str(code: c_int) -> &'static str {
     match code {
         super::SQLITE_OK        => "Successful result",

libsqlite3-sys/src/lib.rs

@@ -12,12 +12,14 @@ use std::mem;
 
 mod error;
 
+#[must_use]
 pub fn SQLITE_STATIC() -> sqlite3_destructor_type {
     None
 }
 
+#[must_use]
 pub fn SQLITE_TRANSIENT() -> sqlite3_destructor_type {
-    Some(unsafe { mem::transmute(-1isize) })
+    Some(unsafe { mem::transmute(-1_isize) })
 }
 
 /// Run-Time Limit Categories

src/backup.rs

@@ -107,7 +107,7 @@ impl Connection {
         let restore = Backup::new_with_names(&src, DatabaseName::Main, self, name)?;
 
         let mut r = More;
-        let mut busy_count = 0i32;
+        let mut busy_count = 0_i32;
         'restore_loop: while r == More || r == Busy {
             r = restore.step(100)?;
             if let Some(ref f) = progress {
@@ -231,6 +231,7 @@ impl Backup<'_, '_> {
     /// Gets the progress of the backup as of the last call to
     /// [`step`](Backup::step).
     #[inline]
+    #[must_use]
     pub fn progress(&self) -> Progress {
         unsafe {
             Progress {
@@ -296,7 +297,7 @@ impl Backup<'_, '_> {
         loop {
             let r = self.step(pages_per_step)?;
             if let Some(progress) = progress {
-                progress(self.progress())
+                progress(self.progress());
             }
             match r {
                 More | Busy | Locked => thread::sleep(pause_between_pages),

src/blob/mod.rs

@@ -265,12 +265,14 @@ impl Blob<'_> {
 
     /// Return the size in bytes of the BLOB.
     #[inline]
+    #[must_use]
     pub fn size(&self) -> i32 {
         unsafe { ffi::sqlite3_blob_bytes(self.blob) }
     }
 
     /// Return the current size in bytes of the BLOB.
     #[inline]
+    #[must_use]
     pub fn len(&self) -> usize {
         use std::convert::TryInto;
         self.size().try_into().unwrap()
@@ -278,6 +280,7 @@ impl Blob<'_> {
 
     /// Return true if the BLOB is empty.
     #[inline]
+    #[must_use]
     pub fn is_empty(&self) -> bool {
         self.size() == 0
     }

src/cache.rs

@@ -46,13 +46,13 @@ impl Connection {
     /// can set the capacity manually using this method.
     #[inline]
     pub fn set_prepared_statement_cache_capacity(&self, capacity: usize) {
-        self.cache.set_capacity(capacity)
+        self.cache.set_capacity(capacity);
     }
 
     /// Remove/finalize all prepared statements currently in the cache.
     #[inline]
     pub fn flush_prepared_statement_cache(&self) {
-        self.cache.flush()
+        self.cache.flush();
     }
 }
 
@@ -122,7 +122,7 @@ impl StatementCache {
 
     #[inline]
     fn set_capacity(&self, capacity: usize) {
-        self.0.borrow_mut().set_capacity(capacity)
+        self.0.borrow_mut().set_capacity(capacity);
     }
 
     // Search the cache for a prepared-statement object that implements `sql`.
@@ -169,7 +169,7 @@ impl StatementCache {
     #[inline]
     fn flush(&self) {
         let mut cache = self.0.borrow_mut();
-        cache.clear()
+        cache.clear();
     }
 }
 

src/column.rs

@@ -12,12 +12,14 @@ pub struct Column<'stmt> {
 impl Column<'_> {
     /// Returns the name of the column.
     #[inline]
+    #[must_use]
     pub fn name(&self) -> &str {
         self.name
     }
 
     /// Returns the type of the column (`None` for expression).
     #[inline]
+    #[must_use]
     pub fn decl_type(&self) -> Option<&str> {
         self.decl_type
     }

src/config.rs

@@ -64,17 +64,17 @@ pub enum DbConfig {
 impl Connection {
     /// Returns the current value of a `config`.
     ///
-    /// - SQLITE_DBCONFIG_ENABLE_FKEY: return `false` or `true` to indicate
+    /// - `SQLITE_DBCONFIG_ENABLE_FKEY`: return `false` or `true` to indicate
     ///   whether FK enforcement is off or on
-    /// - SQLITE_DBCONFIG_ENABLE_TRIGGER: return `false` or `true` to indicate
+    /// - `SQLITE_DBCONFIG_ENABLE_TRIGGER`: return `false` or `true` to indicate
     ///   whether triggers are disabled or enabled
-    /// - SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER: return `false` or `true` to
+    /// - `SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER`: return `false` or `true` to
-    ///   indicate whether fts3_tokenizer are disabled or enabled
+    ///   indicate whether `fts3_tokenizer` are disabled or enabled
-    /// - SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE: return `false` to indicate
+    /// - `SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE`: return `false` to indicate
     ///   checkpoints-on-close are not disabled or `true` if they are
-    /// - SQLITE_DBCONFIG_ENABLE_QPSG: return `false` or `true` to indicate
+    /// - `SQLITE_DBCONFIG_ENABLE_QPSG`: return `false` or `true` to indicate
     ///   whether the QPSG is disabled or enabled
-    /// - SQLITE_DBCONFIG_TRIGGER_EQP: return `false` to indicate
+    /// - `SQLITE_DBCONFIG_TRIGGER_EQP`: return `false` to indicate
     ///   output-for-trigger are not disabled or `true` if it is
     #[inline]
     pub fn db_config(&self, config: DbConfig) -> Result<bool> {
@@ -93,17 +93,17 @@ impl Connection {
 
     /// Make configuration changes to a database connection
     ///
-    /// - SQLITE_DBCONFIG_ENABLE_FKEY: `false` to disable FK enforcement, `true`
+    /// - `SQLITE_DBCONFIG_ENABLE_FKEY`: `false` to disable FK enforcement, `true`
     ///   to enable FK enforcement
-    /// - SQLITE_DBCONFIG_ENABLE_TRIGGER: `false` to disable triggers, `true` to
+    /// - `SQLITE_DBCONFIG_ENABLE_TRIGGER`: `false` to disable triggers, `true` to
     ///   enable triggers
-    /// - SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER: `false` to disable
+    /// - `SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER`: `false` to disable
-    ///   fts3_tokenizer(), `true` to enable fts3_tokenizer()
+    ///   `fts3_tokenizer()`, `true` to enable `fts3_tokenizer()`
-    /// - SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE: `false` (the default) to enable
+    /// - `SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE`: `false` (the default) to enable
     ///   checkpoints-on-close, `true` to disable them
-    /// - SQLITE_DBCONFIG_ENABLE_QPSG: `false` to disable the QPSG, `true` to
+    /// - `SQLITE_DBCONFIG_ENABLE_QPSG`: `false` to disable the QPSG, `true` to
     ///   enable QPSG
-    /// - SQLITE_DBCONFIG_TRIGGER_EQP: `false` to disable output for trigger
+    /// - `SQLITE_DBCONFIG_TRIGGER_EQP`: `false` to disable output for trigger
     ///   programs, `true` to enable it
     #[inline]
     pub fn set_db_config(&self, config: DbConfig, new_val: bool) -> Result<bool> {

src/context.rs

@@ -58,7 +58,7 @@ pub(super) unsafe fn set_result(ctx: *mut sqlite3_context, result: &ToSqlOutput<
             if length > c_int::max_value() as usize {
                 ffi::sqlite3_result_error_toobig(ctx);
             } else if length == 0 {
-                ffi::sqlite3_result_zeroblob(ctx, 0)
+                ffi::sqlite3_result_zeroblob(ctx, 0);
             } else {
                 ffi::sqlite3_result_blob(
                     ctx,

src/functions.rs

@@ -84,21 +84,18 @@ unsafe fn report_error(ctx: *mut sqlite3_context, err: &Error) {
         ffi::SQLITE_CONSTRAINT
     }
 
-    match *err {
+    if let Error::SqliteFailure(ref err, ref s) = *err {
-        Error::SqliteFailure(ref err, ref s) => {
         ffi::sqlite3_result_error_code(ctx, err.extended_code);
         if let Some(Ok(cstr)) = s.as_ref().map(|s| str_to_cstring(s)) {
             ffi::sqlite3_result_error(ctx, cstr.as_ptr(), -1);
         }
-        }
+    } else {
-        _ => {
         ffi::sqlite3_result_error_code(ctx, constraint_error_code());
         if let Ok(cstr) = str_to_cstring(&err.to_string()) {
             ffi::sqlite3_result_error(ctx, cstr.as_ptr(), -1);
         }
     }
 }
-}
 
 unsafe extern "C" fn free_boxed_value<T>(p: *mut c_void) {
     drop(Box::from_raw(p.cast::<T>()));
@@ -114,12 +111,14 @@ pub struct Context<'a> {
 impl Context<'_> {
     /// Returns the number of arguments to the function.
     #[inline]
+    #[must_use]
     pub fn len(&self) -> usize {
         self.args.len()
     }
 
     /// Returns `true` when there is no argument.
     #[inline]
+    #[must_use]
     pub fn is_empty(&self) -> bool {
         self.args.is_empty()
     }
@@ -157,6 +156,7 @@ impl Context<'_> {
     /// Will panic if `idx` is greater than or equal to
     /// [`self.len()`](Context::len).
     #[inline]
+    #[must_use]
     pub fn get_raw(&self, idx: usize) -> ValueRef<'_> {
         let arg = self.args[idx];
         unsafe { ValueRef::from_value(arg) }
@@ -200,7 +200,7 @@ impl Context<'_> {
                 arg,
                 raw.cast(),
                 Some(free_boxed_value::<AuxInner>),
-            )
+            );
         };
         Ok(orig)
     }
@@ -287,7 +287,7 @@ where
     fn finalize(&self, _: &mut Context<'_>, _: Option<A>) -> Result<T>;
 }
 
-/// WindowAggregate is the callback interface for
+/// `WindowAggregate` is the callback interface for
 /// user-defined aggregate window function.
 #[cfg(feature = "window")]
 #[cfg_attr(docsrs, doc(cfg(feature = "window")))]
@@ -617,12 +617,11 @@ unsafe extern "C" fn call_boxed_step<A, D, T>(
     D: Aggregate<A, T>,
     T: ToSql,
 {
-    let pac = match aggregate_context(ctx, ::std::mem::size_of::<*mut A>()) {
+    let pac = if let Some(pac) = aggregate_context(ctx, ::std::mem::size_of::<*mut A>()) {
-        Some(pac) => pac,
+        pac
-        None => {
+    } else {
         ffi::sqlite3_result_error_nomem(ctx);
         return;
-        }
     };
 
     let r = catch_unwind(|| {
@@ -665,12 +664,11 @@ unsafe extern "C" fn call_boxed_inverse<A, W, T>(
     W: WindowAggregate<A, T>,
     T: ToSql,
 {
-    let pac = match aggregate_context(ctx, ::std::mem::size_of::<*mut A>()) {
+    let pac = if let Some(pac) = aggregate_context(ctx, ::std::mem::size_of::<*mut A>()) {
-        Some(pac) => pac,
+        pac
-        None => {
+    } else {
         ffi::sqlite3_result_error_nomem(ctx);
         return;
-        }
     };
 
     let r = catch_unwind(|| {

src/hooks.rs

@@ -367,8 +367,8 @@ impl Connection {
     ///
     /// The callback parameters are:
     ///
-    /// - the type of database update (SQLITE_INSERT, SQLITE_UPDATE or
+    /// - the type of database update (`SQLITE_INSERT`, `SQLITE_UPDATE` or
-    /// SQLITE_DELETE),
+    /// `SQLITE_DELETE`),
     /// - the name of the database ("main", "temp", ...),
     /// - the name of the table that is updated,
     /// - the ROWID of the row that is updated.
@@ -402,7 +402,7 @@ impl Connection {
     where
         F: for<'r> FnMut(AuthContext<'r>) -> Authorization + Send + RefUnwindSafe + 'static,
     {
-        self.db.borrow_mut().authorizer(hook)
+        self.db.borrow_mut().authorizer(hook);
     }
 }
 
@@ -577,8 +577,7 @@ impl InnerConnection {
             }
         }
 
-        match handler {
+        if let Some(handler) = handler {
-            Some(handler) => {
             let boxed_handler = Box::new(handler);
             unsafe {
                 ffi::sqlite3_progress_handler(
@@ -586,14 +585,12 @@ impl InnerConnection {
                     num_ops,
                     Some(call_boxed_closure::<F>),
                     &*boxed_handler as *const F as *mut _,
-                    )
+                );
             }
             self.progress_handler = Some(boxed_handler);
-            }
+        } else {
-            _ => {
             unsafe { ffi::sqlite3_progress_handler(self.db(), num_ops, None, ptr::null_mut()) }
             self.progress_handler = None;
-            }
         };
     }
 
@@ -629,8 +626,7 @@ impl InnerConnection {
                 let boxed_hook: *mut F = p_arg.cast::<F>();
                 (*boxed_hook)(auth_ctx)
             })
-            .map(Authorization::into_raw)
+            .map_or_else(|_| ffi::SQLITE_ERROR, Authorization::into_raw)
-            .unwrap_or_else(|_| ffi::SQLITE_ERROR)
         }
 
         let callback_fn = authorizer
@@ -644,8 +640,7 @@ impl InnerConnection {
                 callback_fn,
                 boxed_authorizer
                     .as_ref()
-                    .map(|f| &**f as *const F as *mut _)
+                    .map_or_else(ptr::null_mut, |f| &**f as *const F as *mut _),
-                    .unwrap_or_else(ptr::null_mut),
             )
         } {
             ffi::SQLITE_OK => {

src/lib.rs

@@ -450,7 +450,7 @@ impl Connection {
     ///
     /// # Failure
     ///
-    /// Will return `Err` if vfs` cannot be converted to a C-compatible
+    /// Will return `Err` if `vfs` cannot be converted to a C-compatible
     /// string or if the underlying SQLite open call fails.
     #[inline]
     pub fn open_in_memory_with_flags_and_vfs(flags: OpenFlags, vfs: &str) -> Result<Connection> {

src/params.rs

@@ -99,7 +99,7 @@ use sealed::Sealed;
 ///
 /// - As a slice of `&[(&str, &dyn ToSql)]`. This is what essentially all of
 ///   these boil down to in the end, conceptually at least. In theory you can
-///   pass this as `stmt.
+///   pass this as `stmt`.
 ///
 /// - As array references, similar to the positional params. This looks like
 ///   `thing.query(&[(":foo", &1i32), (":bar", &2i32)])` or

src/pragma.rs

@@ -143,7 +143,7 @@ impl Sql {
             if ch == quote {
                 self.buf.push(ch);
             }
-            self.buf.push(ch)
+            self.buf.push(ch);
         }
         self.buf.push(quote);
     }

src/raw_statement.rs

@@ -1,5 +1,6 @@
 use super::ffi;
 use super::StatementStatus;
+use crate::util::ParamIndexCache;
 #[cfg(feature = "modern_sqlite")]
 use crate::util::SqliteMallocString;
 use std::ffi::CStr;
@@ -13,7 +14,7 @@ pub struct RawStatement {
     ptr: *mut ffi::sqlite3_stmt,
     tail: usize,
     // Cached indices of named parameters, computed on the fly.
-    cache: crate::util::ParamIndexCache,
+    cache: ParamIndexCache,
     // Cached SQL (trimmed) that we use as the key when we're in the statement
     // cache. This is None for statements which didn't come from the statement
     // cache.
@@ -33,7 +34,7 @@ impl RawStatement {
         RawStatement {
             ptr: stmt,
             tail,
-            cache: Default::default(),
+            cache: ParamIndexCache::default(),
             statement_cache_key: None,
         }
     }

src/row.rs

@@ -80,6 +80,7 @@ impl<'stmt> Rows<'stmt> {
     }
 
     /// Give access to the underlying statement
+    #[must_use]
     pub fn as_ref(&self) -> Option<&Statement<'stmt>> {
         self.stmt
     }
@@ -187,7 +188,7 @@ where
 
 /// `FallibleStreamingIterator` differs from the standard library's `Iterator`
 /// in two ways:
-/// * each call to `next` (sqlite3_step) can fail.
+/// * each call to `next` (`sqlite3_step`) can fail.
 /// * returned `Row` is valid until `next` is called again or `Statement` is
 ///   reset or finalized.
 ///
@@ -209,8 +210,8 @@ impl<'stmt> FallibleStreamingIterator for Rows<'stmt> {
 
     #[inline]
     fn advance(&mut self) -> Result<()> {
-        match self.stmt {
+        if let Some(stmt) = self.stmt {
-            Some(stmt) => match stmt.step() {
+            match stmt.step() {
                 Ok(true) => {
                     self.row = Some(Row { stmt });
                     Ok(())
@@ -225,13 +226,12 @@ impl<'stmt> FallibleStreamingIterator for Rows<'stmt> {
                     self.row = None;
                     Err(e)
                 }
-            },
+            }
-            None => {
+        } else {
             self.row = None;
             Ok(())
         }
     }
-    }
 
     #[inline]
     fn get(&self) -> Option<&Row<'stmt>> {

src/trace.rs

@@ -31,19 +31,18 @@ pub unsafe fn config_log(callback: Option<fn(c_int, &str)>) -> Result<()> {
         let callback: fn(c_int, &str) = unsafe { mem::transmute(p_arg) };
 
         let s = String::from_utf8_lossy(c_slice);
-        let _ = catch_unwind(|| callback(err, &s));
+        drop(catch_unwind(|| callback(err, &s)));
     }
 
-    let rc = match callback {
+    let rc = if let Some(f) = callback {
-        Some(f) => ffi::sqlite3_config(
+        ffi::sqlite3_config(
             ffi::SQLITE_CONFIG_LOG,
             log_callback as extern "C" fn(_, _, _),
             f as *mut c_void,
-        ),
+        )
-        None => {
+    } else {
         let nullptr: *mut c_void = ptr::null_mut();
         ffi::sqlite3_config(ffi::SQLITE_CONFIG_LOG, nullptr, nullptr)
-        }
     };
 
     if rc == ffi::SQLITE_OK {
@@ -75,7 +74,7 @@ impl Connection {
             let trace_fn: fn(&str) = mem::transmute(p_arg);
             let c_slice = CStr::from_ptr(z_sql).to_bytes();
             let s = String::from_utf8_lossy(c_slice);
-            let _ = catch_unwind(|| trace_fn(&s));
+            drop(catch_unwind(|| trace_fn(&s)));
         }
 
         let c = self.db.borrow_mut();
@@ -109,7 +108,7 @@ impl Connection {
                 nanoseconds / NANOS_PER_SEC,
                 (nanoseconds % NANOS_PER_SEC) as u32,
             );
-            let _ = catch_unwind(|| profile_fn(&s, duration));
+            drop(catch_unwind(|| profile_fn(&s, duration)));
         }
 
         let c = self.db.borrow_mut();

src/transaction.rs

@@ -169,6 +169,7 @@ impl Transaction<'_> {
     /// Get the current setting for what happens to the transaction when it is
     /// dropped.
     #[inline]
+    #[must_use]
     pub fn drop_behavior(&self) -> DropBehavior {
         self.drop_behavior
     }
@@ -177,7 +178,7 @@ impl Transaction<'_> {
     /// dropped.
     #[inline]
     pub fn set_drop_behavior(&mut self, drop_behavior: DropBehavior) {
-        self.drop_behavior = drop_behavior
+        self.drop_behavior = drop_behavior;
     }
 
     /// A convenience method which consumes and commits a transaction.
@@ -296,6 +297,7 @@ impl Savepoint<'_> {
     /// Get the current setting for what happens to the savepoint when it is
     /// dropped.
     #[inline]
+    #[must_use]
     pub fn drop_behavior(&self) -> DropBehavior {
         self.drop_behavior
     }
@@ -304,7 +306,7 @@ impl Savepoint<'_> {
     /// dropped.
     #[inline]
     pub fn set_drop_behavior(&mut self, drop_behavior: DropBehavior) {
-        self.drop_behavior = drop_behavior
+        self.drop_behavior = drop_behavior;
     }
 
     /// A convenience method which consumes and commits a savepoint.

src/types/from_sql.rs

@@ -177,7 +177,7 @@ impl FromSql for std::sync::Arc<str> {
 impl FromSql for Vec<u8> {
     #[inline]
     fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
-        value.as_blob().map(|b| b.to_vec())
+        value.as_blob().map(<[u8]>::to_vec)
     }
 }
 
@@ -198,7 +198,7 @@ impl FromSql for i128 {
     #[inline]
     fn column_result(value: ValueRef<'_>) -> FromSqlResult<Self> {
         let bytes = <[u8; 16]>::column_result(value)?;
-        Ok(i128::from_be_bytes(bytes) ^ (1i128 << 127))
+        Ok(i128::from_be_bytes(bytes) ^ (1_i128 << 127))
     }
 }
 

src/types/time.rs

@@ -47,7 +47,7 @@ impl FromSql for OffsetDateTime {
                 len if len <= 19 => {
                     // TODO YYYY-MM-DDTHH:MM:SS
                     PrimitiveDateTime::parse(s, &PRIMITIVE_SHORT_DATE_TIME_FORMAT)
-                        .map(|d| d.assume_utc())
+                        .map(PrimitiveDateTime::assume_utc)
                 }
                 _ if s.as_bytes()[19] == b':' => {
                     // legacy
@@ -56,7 +56,7 @@ impl FromSql for OffsetDateTime {
                 _ if s.as_bytes()[19] == b'.' => OffsetDateTime::parse(s, &OFFSET_DATE_TIME_FORMAT)
                     .or_else(|err| {
                         PrimitiveDateTime::parse(s, &PRIMITIVE_DATE_TIME_FORMAT)
-                            .map(|d| d.assume_utc())
+                            .map(PrimitiveDateTime::assume_utc)
                             .map_err(|_| err)
                     }),
                 _ => OffsetDateTime::parse(s, &OFFSET_SHORT_DATE_TIME_FORMAT),

src/types/value.rs

@@ -47,7 +47,7 @@ impl From<i128> for Value {
     fn from(i: i128) -> Value {
         // We store these biased (e.g. with the most significant bit flipped)
         // so that comparisons with negative numbers work properly.
-        Value::Blob(i128::to_be_bytes(i ^ (1i128 << 127)).to_vec())
+        Value::Blob(i128::to_be_bytes(i ^ (1_i128 << 127)).to_vec())
     }
 }
 
@@ -129,6 +129,7 @@ where
 impl Value {
     /// Returns SQLite fundamental datatype.
     #[inline]
+    #[must_use]
     pub fn data_type(&self) -> Type {
         match *self {
             Value::Null => Type::Null,

src/types/value_ref.rs

@@ -22,6 +22,7 @@ pub enum ValueRef<'a> {
 impl ValueRef<'_> {
     /// Returns SQLite fundamental datatype.
     #[inline]
+    #[must_use]
     pub fn data_type(&self) -> Type {
         match *self {
             ValueRef::Null => Type::Null,

src/unlock_notify.rs

@@ -45,7 +45,7 @@ unsafe extern "C" fn unlock_notify_cb(ap_arg: *mut *mut c_void, n_arg: c_int) {
     use std::slice::from_raw_parts;
     let args = from_raw_parts(ap_arg as *const &UnlockNotification, n_arg as usize);
     for un in args {
-        let _ = catch_unwind(std::panic::AssertUnwindSafe(|| un.fired()));
+        drop(catch_unwind(std::panic::AssertUnwindSafe(|| un.fired())));
     }
 }
 

src/util/small_cstr.rs

@@ -1,7 +1,7 @@
 use smallvec::{smallvec, SmallVec};
 use std::ffi::{CStr, CString, NulError};
 
-/// Similar to std::ffi::CString, but avoids heap allocating if the string is
+/// Similar to `std::ffi::CString`, but avoids heap allocating if the string is
 /// small enough. Also guarantees it's input is UTF-8 -- used for cases where we
 /// need to pass a NUL-terminated string to SQLite, and we have a `&str`.
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
@@ -10,7 +10,7 @@ pub(crate) struct SmallCString(smallvec::SmallVec<[u8; 16]>);
 impl SmallCString {
     #[inline]
     pub fn new(s: &str) -> Result<Self, NulError> {
-        if s.as_bytes().contains(&0u8) {
+        if s.as_bytes().contains(&0_u8) {
             return Err(Self::fabricate_nul_error(s));
         }
         let mut buf = SmallVec::with_capacity(s.len() + 1);
@@ -31,7 +31,7 @@ impl SmallCString {
     /// Get the bytes not including the NUL terminator. E.g. the bytes which
     /// make up our `str`:
     /// - `SmallCString::new("foo").as_bytes_without_nul() == b"foo"`
-    /// - `SmallCString::new("foo").as_bytes_with_nul() == b"foo\0"
+    /// - `SmallCString::new("foo").as_bytes_with_nul() == b"foo\0"`
     #[inline]
     pub fn as_bytes_without_nul(&self) -> &[u8] {
         self.debug_checks();

src/util/sqlite_string.rs

@@ -38,7 +38,7 @@ pub(crate) struct SqliteMallocString {
 
 impl SqliteMallocString {
     /// SAFETY: Caller must be certain that `m` a nul-terminated c string
-    /// allocated by sqlite3_malloc, and that SQLite expects us to free it!
+    /// allocated by `sqlite3_malloc`, and that SQLite expects us to free it!
     #[inline]
     pub(crate) unsafe fn from_raw_nonnull(ptr: NonNull<c_char>) -> Self {
         Self {
@@ -48,7 +48,7 @@ impl SqliteMallocString {
     }
 
     /// SAFETY: Caller must be certain that `m` a nul-terminated c string
-    /// allocated by sqlite3_malloc, and that SQLite expects us to free it!
+    /// allocated by `sqlite3_malloc`, and that SQLite expects us to free it!
     #[inline]
     pub(crate) unsafe fn from_raw(ptr: *mut c_char) -> Option<Self> {
         NonNull::new(ptr).map(|p| Self::from_raw_nonnull(p))
@@ -95,13 +95,13 @@ impl SqliteMallocString {
     /// If `s` contains internal NULs, we'll replace them with
     /// `NUL_REPLACE_CHAR`.
     ///
-    /// Except for debug_asserts which may trigger during testing, this function
+    /// Except for `debug_assert`s which may trigger during testing, this function
     /// never panics. If we hit integer overflow or the allocation fails, we
     /// call `handle_alloc_error` which aborts the program after calling a
     /// global hook.
     ///
     /// This means it's safe to use in extern "C" functions even outside of
-    /// catch_unwind.
+    /// `catch_unwind`.
     pub(crate) fn from_str(s: &str) -> Self {
         use std::convert::TryFrom;
         let s = if s.as_bytes().contains(&0) {

src/version.rs

@@ -6,6 +6,7 @@ use std::ffi::CStr;
 ///
 /// See [`sqlite3_libversion_number()`](https://www.sqlite.org/c3ref/libversion.html).
 #[inline]
+#[must_use]
 pub fn version_number() -> i32 {
     unsafe { ffi::sqlite3_libversion_number() }
 }
@@ -14,6 +15,7 @@ pub fn version_number() -> i32 {
 ///
 /// See [`sqlite3_libversion()`](https://www.sqlite.org/c3ref/libversion.html).
 #[inline]
+#[must_use]
 pub fn version() -> &'static str {
     let cstr = unsafe { CStr::from_ptr(ffi::sqlite3_libversion()) };
     cstr.to_str()

src/vtab/array.rs

@@ -44,7 +44,7 @@ use crate::{Connection, Result};
 pub(crate) const ARRAY_TYPE: *const c_char = (b"rarray\0" as *const u8).cast::<c_char>();
 
 pub(crate) unsafe extern "C" fn free_array(p: *mut c_void) {
-    let _: Array = Rc::from_raw(p as *const Vec<Value>);
+    drop(Rc::from_raw(p as *const Vec<Value>));
 }
 
 /// Array parameter / pointer
@@ -106,11 +106,11 @@ unsafe impl<'vtab> VTab<'vtab> for ArrayTab {
             }
         }
         if ptr_idx {
-            info.set_estimated_cost(1f64);
+            info.set_estimated_cost(1_f64);
             info.set_estimated_rows(100);
             info.set_idx_num(1);
         } else {
-            info.set_estimated_cost(2_147_483_647f64);
+            info.set_estimated_cost(2_147_483_647_f64);
             info.set_estimated_rows(2_147_483_647);
             info.set_idx_num(0);
         }

src/vtab/mod.rs

@@ -79,7 +79,7 @@ union ModuleZeroHack {
 // structs are allowed to be zeroed.
 const ZERO_MODULE: ffi::sqlite3_module = unsafe {
     ModuleZeroHack {
-        bytes: [0u8; std::mem::size_of::<ffi::sqlite3_module>()],
+        bytes: [0_u8; std::mem::size_of::<ffi::sqlite3_module>()],
     }
     .module
 };
@@ -87,6 +87,7 @@ const ZERO_MODULE: ffi::sqlite3_module = unsafe {
 /// Create a read-only virtual table implementation.
 ///
 /// Step 2 of [Creating New Virtual Table Implementations](https://sqlite.org/vtab.html#creating_new_virtual_table_implementations).
+#[must_use]
 pub fn read_only_module<'vtab, T: CreateVTab<'vtab>>() -> &'static Module<'vtab, T> {
     // The xConnect and xCreate methods do the same thing, but they must be
     // different so that the virtual table is not an eponymous virtual table.
@@ -126,6 +127,7 @@ pub fn read_only_module<'vtab, T: CreateVTab<'vtab>>() -> &'static Module<'vtab,
 /// Create an eponymous only virtual table implementation.
 ///
 /// Step 2 of [Creating New Virtual Table Implementations](https://sqlite.org/vtab.html#creating_new_virtual_table_implementations).
+#[must_use]
 pub fn eponymous_only_module<'vtab, T: VTab<'vtab>>() -> &'static Module<'vtab, T> {
     // A virtual table is eponymous if its xCreate method is the exact same function
     // as the xConnect method For eponymous-only virtual tables, the xCreate
@@ -193,7 +195,7 @@ impl VTabConnection {
 ///
 /// # Safety
 ///
-/// The first item in a struct implementing VTab must be
+/// The first item in a struct implementing `VTab` must be
 /// `rusqlite::sqlite3_vtab`, and the struct must be `#[repr(C)]`.
 ///
 /// ```rust,ignore
@@ -326,6 +328,7 @@ impl IndexInfo {
 
     /// Record WHERE clause constraints.
     #[inline]
+    #[must_use]
     pub fn constraints(&self) -> IndexConstraintIter<'_> {
         let constraints =
             unsafe { slice::from_raw_parts((*self.0).aConstraint, (*self.0).nConstraint as usize) };
@@ -336,6 +339,7 @@ impl IndexInfo {
 
     /// Information about the ORDER BY clause.
     #[inline]
+    #[must_use]
     pub fn order_bys(&self) -> OrderByIter<'_> {
         let order_bys =
             unsafe { slice::from_raw_parts((*self.0).aOrderBy, (*self.0).nOrderBy as usize) };
@@ -346,6 +350,7 @@ impl IndexInfo {
 
     /// Number of terms in the ORDER BY clause
     #[inline]
+    #[must_use]
     pub fn num_of_order_by(&self) -> usize {
         unsafe { (*self.0).nOrderBy as usize }
     }
@@ -448,18 +453,21 @@ pub struct IndexConstraint<'a>(&'a ffi::sqlite3_index_constraint);
 impl IndexConstraint<'_> {
     /// Column constrained.  -1 for ROWID
     #[inline]
+    #[must_use]
     pub fn column(&self) -> c_int {
         self.0.iColumn
     }
 
     /// Constraint operator
     #[inline]
+    #[must_use]
     pub fn operator(&self) -> IndexConstraintOp {
         IndexConstraintOp::from(self.0.op)
     }
 
     /// True if this constraint is usable
     #[inline]
+    #[must_use]
     pub fn is_usable(&self) -> bool {
         self.0.usable != 0
     }
@@ -509,12 +517,14 @@ pub struct OrderBy<'a>(&'a ffi::sqlite3_index_info_sqlite3_index_orderby);
 impl OrderBy<'_> {
     /// Column number
     #[inline]
+    #[must_use]
     pub fn column(&self) -> c_int {
         self.0.iColumn
     }
 
     /// True for DESC.  False for ASC.
     #[inline]
+    #[must_use]
     pub fn is_order_by_desc(&self) -> bool {
         self.0.desc != 0
     }
@@ -581,12 +591,14 @@ pub struct Values<'a> {
 impl Values<'_> {
     /// Returns the number of values.
     #[inline]
+    #[must_use]
     pub fn len(&self) -> usize {
         self.args.len()
     }
 
     /// Returns `true` if there is no value.
     #[inline]
+    #[must_use]
     pub fn is_empty(&self) -> bool {
         self.args.is_empty()
     }
@@ -629,6 +641,7 @@ impl Values<'_> {
 
     /// Turns `Values` into an iterator.
     #[inline]
+    #[must_use]
     pub fn iter(&self) -> ValueIter<'_> {
         ValueIter {
             iter: self.args.iter(),
@@ -720,6 +733,7 @@ impl InnerConnection {
 
 /// Escape double-quote (`"`) character occurrences by
 /// doubling them (`""`).
+#[must_use]
 pub fn escape_double_quote(identifier: &str) -> Cow<'_, str> {
     if identifier.contains('"') {
         // escape quote by doubling them
@@ -729,6 +743,7 @@ pub fn escape_double_quote(identifier: &str) -> Cow<'_, str> {
     }
 }
 /// Dequote string
+#[must_use]
 pub fn dequote(s: &str) -> &str {
     if s.len() < 2 {
         return s;
@@ -746,6 +761,7 @@ pub fn dequote(s: &str) -> &str {
 /// 1 yes true on
 /// 0 no false off
 /// ```
+#[must_use]
 pub fn parse_boolean(s: &str) -> Option<bool> {
     if s.eq_ignore_ascii_case("yes")
         || s.eq_ignore_ascii_case("on")
@@ -919,7 +935,7 @@ where
     let vt = vtab.cast::<T>();
     match (*vt).destroy() {
         Ok(_) => {
-            let _: Box<T> = Box::from_raw(vt);
+            drop(Box::from_raw(vt));
             ffi::SQLITE_OK
         }
         Err(Error::SqliteFailure(err, s)) => {