stdstringstartswith

stdstringstartswith is a hypothetical utility proposed for the C++ standard library that determines whether a given string begins with a specified prefix. Conceptually it provides a single, free-function alternative to the member function approach used by std::string::starts_with, aiming to work with multiple string-like types in a uniform way. As of the latest standards, stdstringstartswith is not part of the official C++ standard; the closest built-in facility is std::string::starts_with introduced in C++20.

Prototype and overloads for discussion typically resemble a small family of overloads that accept common string-like types, such as std::string, std::string_view, and const char*. A representative form might be: bool stdstringstartswith(const std::string& s, const std::string& prefix); bool stdstringstartswith(std::string_view s, std::string_view prefix); and similar overloads for const char* where appropriate. Implementations prefer zero-copy input by using string_view semantics when possible, performing a comparison of the prefix against the start of the string.

Usage and behavior: the function returns true if the input string starts with the provided prefix, and false otherwise. The comparison is case-sensitive by default, and its complexity is linear in the length of the prefix. If the prefix is longer than the string, the result is false.

Relation to existing facilities: stdstringstartswith would be redundant in environments where std::string::starts_with is available (C++20 and later). It may be proposed to improve portability across string types or to align with other language libraries. When portability and standard conformance are priorities, using std::string::starts_with or std::ranges::starts_with (where available) is typically preferred.