long 类型的Hash,就是它自身,如 ①所示 特化模板 template<> struct hash<long> 嗯,长这个样子。 生成Hash值的写法: ① std::hash<long>()(c.no) std::hash<long> 这是一个特化版本,后面加() 意思是产生一个临时对象, 这个对象 就当函数来用,也就是前面说的函数对象, 函数传实参 c.no 实
template <bool ASCII> class StringSearcher<true, ASCII> : private StringSearcherBase { private: /// string to be searched for const uint8_t * const needle; const uint8_t * const needle_end; /// first character in `needle` uint8_t first{}; #ifdef __SSE4_1__ /// vector filled ...
we can always determine which version of a function will be called based solely on the arguments in the function call. If return values were used for differentiation, then we wouldn’t have an easy syntactic way to tell which overload of a function was being called -- we’d also have to...
Calling an undeclared function is poor style in C (See this) and illegal in C++. So is passing arguments to a function using a declaration that doesn’t list argument types: If we save the below program in a .c file and compile it, it works without any error. But, if we save the ...
How to declare a structure in a header that is to be used by multiple files in c? Solution 1: if this structure is to be used by some other file func.c how to do it? In order for a type to be utilized in a file (such as a func.c file), it must be accessible. However, ...