multiple definition linker error after adding a function to a previously linking file
问题 So my program is working fine. Compiling, linking, running, the works. Then, I decide to add a simple function to one of my files, like this: #ifndef UTILITY_HPP #define UTILITY_HPP /* #includes here. There's no circular include, I've checked. */ namespace yarl { namespace utility { (several function declarations and definitions) bool isVowel(const char c) { if(c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') return true; else return false; } } } #endif That function definition is