C：标题中的原型声明和实现的函数声明之间的区别？

I was wondering about little differences between declaration of function prototypes in headers and in .c files. I have a header with some prototype functions and a some .c files with real implementation of these functions. I made some changes in the header, only added "__restrict" qualifier (recognized by gcc). My question is do I have to put the "__restrict" qualifier in .c files to (currently the code compile so I guess the answer is no, but some precision would be appreciated).I was wondering about little differences betwee