cmake_minimum_required(VERSION 2.8.10.2)

project(EnableLanguage-Scope NONE)

function(Enable)
  enable_language(C)
  if(CMAKE_C_COMPILER_LOADED)
    message(STATUS "C was loaded")
  else()
    message(STATUS "C was not loaded")
  endif()
endfunction()

Enable()

if(CMAKE_C_COMPILER_LOADED)
  message(STATUS "C reports as loaded")
else()
  message(STATUS "C reports as not loaded")
endif()