[PATCH] Add __cpp_lib_bind_front macro to header

[Jonathan Wakely]

        * include/std/version (__cpp_lib_bind_front): Add missing macro.

Tested x86_64-linux, committed to trunk. I'll backport t his to
gcc-9-branch too.


This missing macro was found by the following script I used for
testing an installed compiler:

#!/bin/sh

: ${CXX:=$HOME/gcc/latest/bin/g++}

for dialect in c++ gnu++
do
for i in 98 11 14 17 2a;
do
 echo ===$dialect$i===
 echo '#include <bits/stdc++.h>' | $CXX -D_GLIBCXX_VERSION_INCLUDED -E 
-std=$dialect$i -dD -xc++ - | grep '^[[:blank:]]*#[[:blank:]]*define[[:blank:]]*__cpp_' 
| sort -u > /tmp/perfilemacros
 echo '#include <version>' | $CXX -E -std=$dialect$i -dD -xc++ - | grep 
'^[[:blank:]]*#[[:blank:]]*define[[:blank:]]*__cpp_' | sort -u > /tmp/versionmacros
 diff -up /tmp/perfilemacros /tmp/versionmacros
done
done



commit e3cc480c4e4601ee97baa96d36952331ffc867d4
Author: redi <redi@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Fri Jun 14 14:03:16 2019 +0000

    Add __cpp_lib_bind_front macro to <version> header
    
            * include/std/version (__cpp_lib_bind_front): Add missing macro.
    
    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@272288 
138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
index cef4f1f8e9c..e300fc38bc7 100644
--- a/libstdc++-v3/include/std/version
+++ b/libstdc++-v3/include/std/version
@@ -150,6 +150,7 @@
 
 #if __cplusplus > 201703L
 // c++2a
+#define __cpp_lib_bind_front 201902L
 #define __cpp_lib_bounded_array_traits 201902L
 #if __cpp_impl_destroying_delete
 # define __cpp_lib_destroying_delete 201806L