From 761df93a83622ce3e05ad9330257ec5459fd8d74 Mon Sep 17 00:00:00 2001
From: zero-systems <60021149+zero-systems@users.noreply.github.com>
Date: Sun, 29 Mar 2020 02:53:03 +1000
Subject: [PATCH] Impls of ToSql for different generic types (Box, Cow, Rc,
 Arc). (#660)
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* Impl ToSql for Box<str>

* Add generic impls for Cow, Box, Rc, Arc. Remove impl for Box<str>

* Remove impl of ToSql for Cow<'_, str>

* Add missing as_ref

Co-authored-by: Øsystems <>
---
 src/types/to_sql.rs | 56 ++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 50 insertions(+), 6 deletions(-)

diff --git a/src/types/to_sql.rs b/src/types/to_sql.rs
index 3a7481a..b4a27b6 100644
--- a/src/types/to_sql.rs
+++ b/src/types/to_sql.rs
@@ -94,6 +94,33 @@ impl ToSql for Box<dyn ToSql> {
     }
 }
 
+impl<T: ToSql + Clone> ToSql for Cow<'_, T> {
+    fn to_sql(&self) -> Result<ToSqlOutput<'_>> {
+        self.as_ref().to_sql()
+    }
+}
+
+impl<T: ToSql> ToSql for Box<T> {
+    fn to_sql(&self) -> Result<ToSqlOutput<'_>> {
+        let derefed: &dyn ToSql = &**self;
+        derefed.to_sql()
+    }
+}
+
+impl<T: ToSql> ToSql for std::rc::Rc<T> {
+    fn to_sql(&self) -> Result<ToSqlOutput<'_>> {
+        let derefed: &dyn ToSql = &**self;
+        derefed.to_sql()
+    }
+}
+
+impl<T: ToSql> ToSql for std::sync::Arc<T> {
+    fn to_sql(&self) -> Result<ToSqlOutput<'_>> {
+        let derefed: &dyn ToSql = &**self;
+        derefed.to_sql()
+    }
+}
+
 // We should be able to use a generic impl like this:
 //
 // impl<T: Copy> ToSql for T where T: Into<Value> {
@@ -182,12 +209,6 @@ impl<T: ToSql> ToSql for Option<T> {
     }
 }
 
-impl ToSql for Cow<'_, str> {
-    fn to_sql(&self) -> Result<ToSqlOutput<'_>> {
-        Ok(ToSqlOutput::from(self.as_ref()))
-    }
-}
-
 #[cfg(test)]
 mod test {
     use super::ToSql;
@@ -217,6 +238,29 @@ mod test {
         assert!(r.is_ok());
     }
 
+    #[test]
+    fn test_box() {
+        let s: Box<str> = "Hello world!".into();
+        let r = s.to_sql();
+
+        assert!(r.is_ok());
+    }
+
+    #[test]
+    fn test_cells() {
+        use std::{rc::Rc, sync::Arc};
+
+        let source_str: Box<str> = "Hello world!".into();
+
+        let s: Rc<_> = Rc::new(source_str.clone());
+        let r = s.to_sql();
+        assert!(r.is_ok());
+
+        let s: Arc<_> = Arc::new(source_str);
+        let r = s.to_sql();
+        assert!(r.is_ok());
+    }
+
     #[cfg(feature = "i128_blob")]
     #[test]
     fn test_i128() {