Compiling software with c++11 support

[Jakub Sochor]

Hello,

i have a question about the c++11 support. 
Is in MacPorts some configuration that will force use all c++ sources to be compiled by host clang with flags '-std=c++11 -stdlib=libc++'.
I tried configure.cxxflags but that had no effect in OpenCV for example. 

Can you please give me some pointers what should I do, or if it is even possible. 

Thank you,
Jakub Sochor