Replace the macro_rules based __diesel_for_each_tuple macro with an

proc macro

This allows to generate a single macro call per call of
`__diesel_for_each_tuple`, which helps to implement the column count
checking in a simpler way.

Compile time wise this seems to be the same as before. I've measured the
following times:

	with proc macro 	with macro_rules
16	22.88 s			28.18 s
32	36.03 s			36.08 s
64	1 min 47s		1min 74s

Author: weiznich

diesel/Cargo.toml

@@ -49,9 +49,9 @@ extras = ["chrono", "serde_json", "uuid", "network-address", "numeric", "r2d2"]
 unstable = ["diesel_derives/nightly"]
 large-tables = ["32-column-tables"]
 huge-tables = ["64-column-tables"]
-32-column-tables = []
-64-column-tables = ["32-column-tables"]
-128-column-tables = ["64-column-tables"]
+32-column-tables = ["diesel_derives/32-column-tables"]
+64-column-tables = ["32-column-tables", "diesel_derives/64-column-tables"]
+128-column-tables = ["64-column-tables", "diesel_derives/128-column-tables"]
 postgres = ["pq-sys", "postgres_backend"]
 sqlite = ["libsqlite3-sys", "diesel_derives/sqlite"]
 mysql = ["mysqlclient-sys", "url", "percent-encoding", "bitflags", "mysql_backend"]

diesel/src/expression_methods/eq_all.rs

@@ -69,4 +69,4 @@ macro_rules! impl_eq_all_for_all_tuples {
     };
 }
 
-__diesel_for_each_tuple!(impl_eq_all_for_all_tuples);
+diesel_derives::__diesel_for_each_tuple!(impl_eq_all_for_all_tuples);

diesel/src/lib.rs

@@ -171,7 +171,10 @@ mod util;
 #[doc(hidden)]
 #[cfg(all(feature = "with-deprecated", not(feature = "without-deprecated")))]
 #[deprecated(since = "2.0.0", note = "Use explicit macro imports instead")]
-pub use diesel_derives::*;
+pub use diesel_derives::{
+    AsChangeset, AsExpression, Associations, DieselNumericOps, FromSqlRow, Identifiable,
+    Insertable, QueryId, Queryable, QueryableByName, SqlType,
+};
 
 pub mod dsl {
     //! Includes various helper types and bare functions which are named too

diesel/src/macros/mod.rs

@@ -1370,16 +1370,12 @@ macro_rules! impl_column_check {
                         $crate::__diesel_error_table_size!();
                     }
                 }
-
-                // workaround https://github.com/rust-lang/rust/pull/52234
-                #[doc(hidden)]
-                pub use __diesel_check_column_count_internal as __diesel_check_column_count;
             }
         }
     }
 }
 
-crate::__diesel_for_each_tuple!(impl_column_check);
+diesel_derives::__diesel_for_each_tuple!(impl_column_check);
 
 #[cfg(not(any(
     feature = "32-column-tables",
@@ -1458,8 +1454,7 @@ mod internal;
 mod static_cond;
 #[macro_use]
 mod ops;
-#[macro_use]
-mod tuples;
+
 
 #[cfg(test)]
 mod tests {