Check if one string is a prefix of another

Question

I have two strings which I\'d like to compare: String and String:. Is there a library function that would return true when passed these two strings

Answer 1

You can use this:

for c++14 or less

bool has_prefix
    (const std::string& str, const std::string& prefix)  {
    return str.find(prefix, 0) == 0;
}

for c++17

//it's a little faster
auto has_prefix
    (const std::string& str, const std::string_view& prefix) -> decltype(str.find(prefix) == 0) {
    return str.find(prefix, 0) == 0;
}