-std=c++14 after -std=c++11 in my build command, which wins?

Asked Feb 10 '20 at 19:31

Active Feb 10 '20 at 19:36

Viewed 228 times

I have both options on in my Makefile, Basically, my Make file looks like this

$OPT_FLAG := -O2 -std=c++11 $CXXFLAG += $(OPT_FLAG) -std=c++14

so actual build command is sth like

g++ -m64 ... -std=c++11, -std=c++14 ...

and of course $CXXFLAG is passed as argument to invoke gcc build. In this case, am I using c++14 or c++11? my gcc version is 5.4

edited Feb 10 '20 at 19:32

Jonathon Reinhart

asked Feb 10 '20 at 19:31

user6938419

3

IIRC it is the rightmost option that is chosen. Trying to find a dupe target – NathanOliver Feb 10 '20 at 19:34
https://stackoverflow.com/questions/15909788/how-does-gcc-behave-if-passed-conflicting-compiler-flags – Mat Feb 10 '20 at 19:35
i added another duplicate, it is about `-Ox` but still I thought it is related enough to add it – 463035818_is_not_an_ai Feb 10 '20 at 19:37
2

Is there more to this than checking what `__cplusplus` is, and checking if it's consistent depending on the order you pass? – Bathsheba Feb 10 '20 at 19:40

0 Answers0