c++ - Is there such thing as implicit declaration in c++?

Question

I was burnt just now. I hadn't enabled warnings while compiling my c code. I was using atof without including stdlib.h. So the atof was using implicit declaration which had default return type of int. So the code wasn't working. I was wondering if the concept of implicit declarations also applies to c++?

Answer 1

C++ 不允许隐式函数声明。事实上，即使是 C99/11 也不允许它们。GCC 默认将 C 编译为 C89，这就是您遇到错误的原因。