gentoo-overlay/mail-client/trojita/files/trojita-0.7-cmake-cxx11.patch

From e2e35bfda75a2f4950408c93ede72fabfe86360e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kundr=C3=A1t?= <jkt@kde.org>
Date: Wed, 19 Oct 2016 22:15:16 +0200
Subject: [PATCH] cmake: Speed up cmake by using native features for enforcing
 C++11

This saves about 8 seconds in my (limited) testing with a 2016-era
laptop with plenty of RAM and a fast SSD.

We still attempt to support ancient pre-3.1 CMake by adding that blurb
into CXXFLAGS, maybe it even works.

I should probably start tracking time I spend supporting old
environments and evaluate whether this is worth the effort. Once we are
ready to distribute flatpaks/appimages/whatevers, I suspect that my life
will become much easier.

Change-Id: Ibbbe3d8440a7d29ef27440a99938d313bfe9699f
---
 CMakeLists.txt                                |  26 ++--
 24 files changed, 8 insertions(+), 468 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9393b19c..92a682f7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -18,6 +18,14 @@ if(POLICY CMP0043)
     cmake_policy(SET CMP0043 OLD)
 endif()
 
+if(CMAKE_VERSION VERSION_LESS "3.1")
+    # If you aren't using and old Linux with an old GCC and old CMake, please just upgrade.
+    set(CMAKE_CXX_FLAGS "--std=c++11 ${CMAKE_CXX_FLAGS}")
+else()
+    set(CMAKE_CXX_STANDARD 11)
+    set(CMAKE_CXX_STANDARD_REQUIRED ON)
+endif()
+
 # Set a default build type if none was specified. This was shamelessly stolen
 # from VTK's cmake setup because these guys produce both CMake and a project that
 # manipulates this variable, and the web is full of posts where people say that
@@ -34,24 +42,6 @@ endif()
 
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
-include(FindCXXFeatures)
-if(NOT CXXFeatures_auto_FOUND)
-    message(SEND_ERROR "Your compiler doesn't support C++11's auto")
-endif()
-if(NOT CXXFeatures_static_assert_FOUND)
-    message(SEND_ERROR "Your compiler doesn't support C++11's static_assert")
-endif()
-if(NOT CXXFeatures_alignof_FOUND)
-    message(SEND_ERROR "Your compiler doesn't support C++11's alignof")
-endif()
-if(NOT CXXFeatures_nullptr_FOUND)
-    message(SEND_ERROR "Your compiler doesn't support C++11's nullptr")
-endif()
-if(NOT CXXFeatures_lambda_FOUND)
-    message(SEND_ERROR "Your compiler doesn't support C++11's lambda functions")
-endif()
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CXX11_COMPILER_FLAGS}")
-
 include(TrojitaOption)
 
 trojita_option(WITH_DESKTOP "Build desktop version" ON)