Fix handful of clippy warnings.

src/error.rs

@@ -166,7 +166,6 @@ impl error::Error for Error {
     fn cause(&self) -> Option<&error::Error> {
         match *self {
             Error::SqliteFailure(ref err, _) => Some(err),
-            Error::FromSqlConversionFailure(_, _, ref err) => Some(&**err),
             Error::Utf8Error(ref err) => Some(err),
             Error::NulError(ref err) => Some(err),
 
@@ -186,6 +185,8 @@ impl error::Error for Error {
 
             #[cfg(feature = "functions")]
             Error::UserFunctionError(ref err) => Some(&**err),
+
+            Error::FromSqlConversionFailure(_, _, ref err) |
             Error::ToSqlConversionFailure(ref err) => Some(&**err),
         }
     }

src/types/from_sql.rs

@@ -61,12 +61,24 @@ pub trait FromSql: Sized {
     fn column_result(value: ValueRef) -> FromSqlResult<Self>;
 }
 
+impl FromSql for isize {
+    fn column_result(value: ValueRef) -> FromSqlResult<Self> {
+        i64::column_result(value).and_then(|i| {
+            if i < isize::min_value() as i64 || i > isize::max_value() as i64 {
+                Err(FromSqlError::OutOfRange(i))
+            } else {
+                Ok(i as isize)
+            }
+        })
+    }
+}
+
 macro_rules! from_sql_integral(
     ($t:ident) => (
         impl FromSql for $t {
             fn column_result(value: ValueRef) -> FromSqlResult<Self> {
                 i64::column_result(value).and_then(|i| {
-                    if i < $t::min_value() as i64 || i > $t::max_value() as i64 {
+                    if i < i64::from($t::min_value()) || i > i64::from($t::max_value()) {
                         Err(FromSqlError::OutOfRange(i))
                     } else {
                         Ok(i as $t)
@@ -80,7 +92,6 @@ macro_rules! from_sql_integral(
 from_sql_integral!(i8);
 from_sql_integral!(i16);
 from_sql_integral!(i32);
-from_sql_integral!(isize);
 from_sql_integral!(u8);
 from_sql_integral!(u16);
 from_sql_integral!(u32);

src/types/time.rs

@@ -3,7 +3,7 @@ extern crate time;
 use Result;
 use types::{FromSql, FromSqlError, FromSqlResult, ToSql, ToSqlOutput, ValueRef};
 
-const SQLITE_DATETIME_FMT: &'static str = "%Y-%m-%d %H:%M:%S:%f %Z";
+const SQLITE_DATETIME_FMT: &str = "%Y-%m-%d %H:%M:%S:%f %Z";
 
 impl ToSql for time::Timespec {
     fn to_sql(&self) -> Result<ToSqlOutput> {

src/types/to_sql.rs

@@ -84,7 +84,7 @@ impl<'a, T: ?Sized> ToSql for &'a T
     where &'a T: Into<ToSqlOutput<'a>>
 {
     fn to_sql(&self) -> Result<ToSqlOutput> {
-        Ok(ToSqlOutput::from((*self).into()))
+        Ok((*self).into())
     }
 }
 

src/types/value.rs

@@ -30,11 +30,15 @@ impl From<bool> for Value {
     }
 }
 
+impl From<isize> for Value {
+    fn from(i: isize) -> Value { Value::Integer(i as i64) }
+}
+
 macro_rules! from_i64(
     ($t:ty) => (
         impl From<$t> for Value {
             fn from(i: $t) -> Value {
-                Value::Integer(i as i64)
+                Value::Integer(i64::from(i))
             }
         }
     )
@@ -43,7 +47,6 @@ macro_rules! from_i64(
 from_i64!(i8);
 from_i64!(i16);
 from_i64!(i32);
-from_i64!(isize);
 from_i64!(u8);
 from_i64!(u16);
 from_i64!(u32);

src/version.rs

@@ -3,14 +3,14 @@ use std::ffi::CStr;
 
 /// Returns the SQLite version as an integer; e.g., `3016002` for version 3.16.2.
 ///
-/// See [sqlite3_libversion_number()](https://www.sqlite.org/c3ref/libversion.html).
+/// See [`sqlite3_libversion_number()`](https://www.sqlite.org/c3ref/libversion.html).
 pub fn version_number() -> i32 {
     unsafe { ffi::sqlite3_libversion_number() }
 }
 
 /// Returns the SQLite version as a string; e.g., `"3.16.2"` for version 3.16.2.
 ///
-/// See [sqlite3_libversion()](https://www.sqlite.org/c3ref/libversion.html).
+/// See [`sqlite3_libversion()`](https://www.sqlite.org/c3ref/libversion.html).
 pub fn version() -> &'static str {
     let cstr = unsafe { CStr::from_ptr(ffi::sqlite3_libversion()) };
     cstr.to_str()