[CMake] set cpp11-14

CMakeLists.txt

cmake_minimum_required(VERSION 2.8.3)
project(my_project)

# assuming this file is shipped within your project
# in 'project_root/cmake/cxx_support.cmake'
include(${PROJECT_SOURCE_DIR}/cmake/cxx_support.cmake)

# Assert the build was triggered with
# cpp11 flag, cash otherwise.
assert_cpp11_support()

...

## Declare a C++ library
add_library(${PROJECT_NAME}
  ...
)
# Set required C++11 flag
set_cpp11_target(${PROJECT_NAME})

cxx_support.cmake

function(assert_cxx_support cxx)
  # Check that the compoiler has cxx support
  # Crash otherwise.
  include(CheckCXXCompilerFlag)
  CHECK_CXX_COMPILER_FLAG("-std=c++${cxx}" COMPILER_SUPPORTS_CXX${cxx})
  if(COMPILER_SUPPORTS_CXX${cxx})
    message(STATUS "The compiler ${CMAKE_CXX_COMPILER} has C++${cxx} support.")
  else()
    message(FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} has no C++${cxx} support. Please use a different C++ compiler.")
  endif()
endfunction(assert_cxx_support)

macro(assert_cpp11_support)
  assert_cxx_support(11)
endmacro()

macro(assert_cpp14_support)
  assert_cxx_support(14)
endmacro()

function(set_cxx_target cxx)
  foreach(t ${ARGN})
    # Set cxx for target ${a}
    if(CMAKE_VERSION VERSION_LESS "3.1")
      set_target_properties(${t} PROPERTIES COMPILE_FLAGS "-std=c++${cxx}")
    else()
      set_property(TARGET ${t} PROPERTY CXX_STANDARD ${cxx})
      set_property(TARGET ${t} PROPERTY CXX_STANDARD_REQUIRED ON)
      set_property(TARGET ${t} PROPERTY CXX_EXTENSIONS OFF)
    endif()
  endforeach()
endfunction(set_cxx_target)

macro(set_cpp11_target)
  set_cxx_target(11 ${ARGV})
endmacro()

macro(set_cpp14_target)
  set_cxx_target(14 ${ARGV})
endmacro()

set_cxx.cmake

#Global:  
#
#cmake_minimum_required(VERSION 3.2.0 FATAL_ERROR)
#...
#set(PROPERTY CXX_STANDARD 11)  # 98, 11 or 14
#set(PROPERTY CXX_STANDARD_REQUIRED ON)
#set(PROPERTY CXX_EXTENSIONS OFF) # avoid linking to e.g. gnu 
#
#
#Per target:
#
#cmake_minimum_required(VERSION 3.2.0 FATAL_ERROR)
#...
#set_property(TARGET target1 target2 ... PROPERTY CXX_STANDARD 11)  # 98, 11 or 14
#set_property(TARGET target1 target2 ... PROPERTY CXX_STANDARD_REQUIRED ON)
#set_property(TARGET target1 target2 ... PROPERTY CXX_EXTENSIONS OFF)
#
#Per features:
#
#cmake_minimum_required(VERSION 3.2.0 FATAL_ERROR)
#...
#target_compile_features(myTarget
#  PUBLIC
#    cxx_variadic_templates
#    cxx_nullptr
#    ...
#  PRIVATE
#    cxx_lambdas
#    ...
#)

#The above require cmake 3.1.0/3.2.0

function(set_cxx_target cxx)
  foreach(a ${ARGN})
    # Set cxx for target ${a}
    if(CMAKE_VERSION VERSION_LESS "3.1")
      set_target_properties(${a} PROPERTIES COMPILE_FLAGS "-std=c++${cxx}")
    else()
      set_property(TARGET ${a} PROPERTY CXX_STANDARD ${cxx})
      set_property(TARGET ${a} PROPERTY CXX_STANDARD_REQUIRED ON)
      set_property(TARGET ${a} PROPERTY CXX_EXTENSIONS OFF)
    endif()
  endforeach()
endfunction(set_c11_target)

macro(set_c11_target)
  set_cxx_target(11 ARGN)
endmacro()

macro(set_c14_target)
  set_cxx_target(14 ARGN)
endmacro()