cmake: enforce C++ 11 standard

Avoids errors on macOS like:

In file included from crunch/crnlib/crn_threading.h:7:
crunch/crnlib/crn_threading_pthreads.h:177:40: warning: defaulted function
      definitions are a C++11 extension [-Wc++11-extensions]
    virtual ~executable_task( void ) = default;
                                       ^
crunch/crnlib/crn_threading_pthreads.h:253:11: error: exception specification
      of overriding function is more lax than base version
  virtual ~object_task( void ) = default;
          ^
crunch/crnlib/crn_threading_pthreads.h:177:13: note: overridden virtual
      function is here
    virtual ~executable_task( void ) = default;
            ^
crunch/crnlib/crn_threading_pthreads.h:253:34: warning: defaulted function
      definitions are a C++11 extension [-Wc++11-extensions]
  virtual ~object_task( void ) = default;
                                 ^

Author: illwieckz

CMakeLists.txt

@@ -1,5 +1,7 @@
 cmake_minimum_required(VERSION 3.1)
 
+set(CMAKE_CXX_STANDARD 11)
+
 set(CRUNCH_PROJECT_NAME crunch)
 set(CRUNCH_LIBRARY_NAME crn)
 set(CRUNCH_EXE_NAME crunch)

crnlib/Makefile

@@ -7,7 +7,7 @@ COMPILE_CPU_OPTIONS = -march=core2
 COMPILE_DEBUG_OPTIONS = -g
 COMPILE_OPTIMIZATION_OPTIONS = -O3 -fomit-frame-pointer -ffast-math -fno-math-errno -fno-strict-aliasing
 COMPILE_WARN_OPTIONS = -Wall -Wno-unused-value -Wno-unused
-COMPILE_OPTIONS = $(COMPILE_CPU_OPTIONS) $(COMPILE_DEBUG_OPTIONS) $(COMPILE_OPTIMIZATION_OPTIONS) $(COMPILE_WARN_OPTIONS)
+COMPILE_OPTIONS = -std=c++11 $(COMPILE_CPU_OPTIONS) $(COMPILE_DEBUG_OPTIONS) $(COMPILE_OPTIMIZATION_OPTIONS) $(COMPILE_WARN_OPTIONS)
 
 LINKER_OPTIONS = -lpthread -g