Add c++20 support

1 files changed, 124 insertions, 0 deletions

diff --git a/dev-util/boost-build/boost-build-1.73.0-cxx-20.patch b/dev-util/boost-build/boost-build-1.73.0-cxx-20.patch
new file mode 100644
index 0000000..d7e7a15
--- /dev/null
+++ b/dev-util/boost-build/boost-build-1.73.0-cxx-20.patch
@@ -0,0 +1,124 @@
+From 677e2f3d546d8e7f140d97cd8291a81a423e6451 Mon Sep 17 00:00:00 2001
+From: Andrey Semashev <Lastique@users.noreply.github.com>
+Date: Wed, 6 May 2020 18:56:38 +0300
+Subject: [PATCH] Add cxxstd value 20 for C++20 (#592)
+
+* Added cxxstd value 20 for C++20.
+
+The -std=c++20 is supported by clang 10.
+
+* Updated cxxstd=latest for clang 5.0 and newer.
+
+clang 5.0 supports -std=c++17. clang 6.0 supports -std=c++2a.
+clang 10.0 supports -std=c++20.
+
+* Updated cxxstd=latest for gcc.
+
+gcc 4.9 supports -std=c++14. gcc 6 supports -std=c++17. gcc 10 will support
+-std=c++20.
+
+* Added support for cxxstd=20 to toolsets that don't support C++20.
+---
+ src/tools/clang.jam                   | 5 ++++-
+ src/tools/cray.jam                    | 2 +-
+ src/tools/features/cxxstd-feature.jam | 4 ++--
+ src/tools/gcc.jam                     | 5 ++++-
+ src/tools/pgi.jam                     | 1 +
+ src/tools/xlcpp.jam                   | 4 ++++
+ 7 files changed, 18 insertions(+), 5 deletions(-)
+
+diff --git a/tools/clang.jam b/tools/clang.jam
+index bcb3837039..f1850db194 100644
+--- a/tools/clang.jam
++++ b/tools/clang.jam
+@@ -55,7 +55,10 @@ rule init-cxxstd-flags ( toolset : condition * : version )
+     local dialects = [ feature.values <cxxstd-dialect> ] ;
+     dialects = [ set.difference $(dialects) : gnu iso ] ;
+     local std ;
+-    if [ version-ge $(version) : 3.5 ] { std = 1z ; }
++    if [ version-ge $(version) : 10.0 ] { std = 20 ; }
++    else if [ version-ge $(version) : 6.0 ] { std = 2a ; }
++    else if [ version-ge $(version) : 5.0 ] { std = 17 ; }
++    else if [ version-ge $(version) : 3.5 ] { std = 1z ; }
+     else if [ version-ge $(version) : 3.4 ] { std = 14 ; }
+     else if [ version-ge $(version) : 3.3 ] { std = 11 ; }
+     else { std = 03 ; }
+diff --git a/tools/cray.jam b/tools/cray.jam
+index 107b3dbbc5..d586af3af4 100644
+--- a/tools/cray.jam
++++ b/tools/cray.jam
+@@ -707,7 +707,7 @@ rule set-cxxstd-procedure ( targets * : sources * : properties * )
+     local cxxstd = [ feature.get-values cxxstd : $(properties) ] ;
+     local cray-cxxstd = ;
+ 
+-    local unsupported-values = 2a ; # I don't know what '2a' means.
++    local unsupported-values = 2a 20 ; # I don't know what '2a' means.
+     if $(cxxstd) && $(cxxstd) in $(unsupported-values)
+     {
+ 
+diff --git a/tools/features/cxxstd-feature.jam b/tools/features/cxxstd-feature.jam
+index dfddf5bb78..3d7ba8d8cc 100644
+--- a/tools/features/cxxstd-feature.jam
++++ b/tools/features/cxxstd-feature.jam
+@@ -8,7 +8,7 @@ import feature ;
+ #| tag::doc[]
+ 
+ [[bbv2.builtin.features.cxxstd]]`cxxstd`::
+-*Allowed values*: `98`, `03`, `0x`, `11`, `1y`, `14`, `1z`, `17`, `2a`,
++*Allowed values*: `98`, `03`, `0x`, `11`, `1y`, `14`, `1z`, `17`, `2a`, `20`,
+ `latest`.
+ +
+ Specifies the version of the C++ Standard Language to build with. All the
+@@ -28,7 +28,7 @@ is supported.
+ |# # end::doc[]
+ 
+ feature.feature cxxstd
+-    : 98 03 0x 11 1y 14 1z 17 2a latest
++    : 98 03 0x 11 1y 14 1z 17 2a 20 latest
+     : optional composite propagated ;
+ 
+ #| tag::doc[]
+diff --git a/tools/gcc.jam b/tools/gcc.jam
+index 5ceb038fc5..f03336a5d7 100644
+--- a/tools/gcc.jam
++++ b/tools/gcc.jam
+@@ -499,8 +499,11 @@ local rule compile-link-flags ( * )
+     local rule init-cxxstd-flags ( condition * : version )
+     {
+         local std ;
+-        if [ version-ge $(version) : 8 ] { std = 2a ; }
++        if [ version-ge $(version) : 10 ] { std = 20 ; }
++        else if [ version-ge $(version) : 8 ] { std = 2a ; }
++        else if [ version-ge $(version) : 6 ] { std = 17 ; }
+         else if [ version-ge $(version) : 5 ] { std = 1z ; }
++        else if [ version-ge $(version) : 4.9 ] { std = 14 ; }
+         else if [ version-ge $(version) : 4.8 ] { std = 1y ; }
+         else if [ version-ge $(version) : 4.7 ] { std = 11 ; }
+         else if [ version-ge $(version) : 3.3 ] { std = 98 ; }
+diff --git a/tools/pgi.jam b/tools/pgi.jam
+index b59db4d4ec..6eed7759fb 100644
+--- a/tools/pgi.jam
++++ b/tools/pgi.jam
+@@ -57,6 +57,7 @@ flags pgi.compile.c++ OPTIONS <cxxstd>14 : -std=c++14 ;
+ flags pgi.compile.c++ OPTIONS <cxxstd>1z : -std=c++17 ;
+ flags pgi.compile.c++ OPTIONS <cxxstd>17 : -std=c++17 ;
+ flags pgi.compile.c++ OPTIONS <cxxstd>2a : -std=c++17 ;
++flags pgi.compile.c++ OPTIONS <cxxstd>20 : -std=c++17 ;
+ flags pgi.compile.c++ OPTIONS <cxxstd>latest : -std=c++17 ;
+ 
+ flags pgi.compile OPTIONS <link>shared : -fpic ;
+diff --git a/tools/xlcpp.jam b/tools/xlcpp.jam
+index 1b66301cf1..a9e767cefb 100644
+--- a/tools/xlcpp.jam
++++ b/tools/xlcpp.jam
+@@ -112,6 +112,10 @@ flags xlcpp.compile.c++ OPTIONS <cxxstd>0x : -std=c++11 ;
+ flags xlcpp.compile.c++ OPTIONS <cxxstd>11 : -std=c++11 ;
+ flags xlcpp.compile.c++ OPTIONS <cxxstd>1y : -std=c++1y ;
+ flags xlcpp.compile.c++ OPTIONS <cxxstd>14 : -std=c++1y ;
++flags xlcpp.compile.c++ OPTIONS <cxxstd>1z : -std=c++1y ;
++flags xlcpp.compile.c++ OPTIONS <cxxstd>17 : -std=c++1y ;
++flags xlcpp.compile.c++ OPTIONS <cxxstd>2a : -std=c++1y ;
++flags xlcpp.compile.c++ OPTIONS <cxxstd>20 : -std=c++1y ;
+ flags xlcpp.compile.c++ OPTIONS <cxxstd>latest : -std=c++1y ;
+ 
+ flags xlcpp.compile OPTIONS <cflags> ;