[scons] Enable C++14 for all targets by default.

.travis.yml

@@ -14,12 +14,12 @@ addons:
    - libsdl1.2-dev
    - libsdl-image1.2-dev
    - libgtkmm-2.4-dev
-   - g++-4.8
+   - g++-7
    - libzmqpp-dev
 
 before_install:
- - export CC=gcc-4.8
- - export CXX=g++-4.8
+ - export CC=gcc-7
+ - export CXX=g++-7
  - ls -l $HOME/cache
  - bash .travis.dep.sh
  - export LD_LIBRARY_PATH="$HOME/toolchain/boost/lib:$LD_LIBRARY_PATH"

scons/site_tools/arm.py

@@ -170,7 +170,7 @@ def generate(env, **kw):
 	env['CXXFLAGS'] = [
 #		"-fverbose-asm",
 #		"-save-temps",		# save preprocessed files
-		"-std=c++11",
+		"-std=c++14",
 		"-fconstexpr-depth=10000", # enable deep recursion
 		"-fno-exceptions",
 		"-fno-rtti",

scons/site_tools/avr.py

@@ -150,8 +150,7 @@ def generate(env, **kw):
 
 	# C++ flags
 	env['CXXFLAGS'] = [
-#		"-std=gnu++98",
-		"-std=gnu++0x",
+		"-std=c++14",
 		"-fno-exceptions", 
 		"-fno-rtti",
 		"-fno-threadsafe-statics",

scons/site_tools/hosted.py

@@ -100,7 +100,7 @@ def generate(env, **kw):
 
 	# C++ flags
 	env['CXXFLAGS'] = [
-		"-std=c++11",
+		"-std=c++14",
 #		"-Weffc++",
 		"-Woverloaded-virtual",
 	]