3.0beta TestCpp std::string& and std:string->c_str()

cocos2d-x C++
#1

in BaseTest.cpp onEnter,

why use

std::string str = title();
const char * pTitle = str.c_str();
auto label = LabelTTF::create(pTitle, “Arial”, 32);

not use

std::string str = title();
auto label = LabelTTF::create(str, “Arial”, 32);

sorry,not good at English.
Thank you very much.