std::sub_match::compare(3)

💅 std::sub_match::compare — okay bestie, let's get into it

So this is std::sub_match::compare from the C++ Standard Library, and honestly? It's a little niche, but it's ours now, so let's understand it together 🫶

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✨ Synopsis ✨

int compare( const sub_match& m ) const;   (1) (since C++11)
int compare( const string_type& s ) const; (2) (since C++11)
int compare( const value_type* c ) const;  (3) (since C++11)

Three whole overloads, all since C++11, all const, all returning int. Iconic.

1. Compares two sub_match directly, by comparing their underlying character sequences. Literally equivalent to str().compare(m.str()). That's it, that's the whole vibe.
2. Compares a sub_match with a std::basic_string. Equivalent to str().compare(s).
3. Compares a sub_match with a null-terminated sequence of the underlying character type, pointed to by s. Equivalent to str().compare(c).

Real talk though: this function is infrequently used directly by application code. Like, nobody's out here calling it in the group chat. Instead, one of the non-member comparison operators gets used. That's the main character. compare is just vibing backstage 💀

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🎀 Parameters 🎀

• m — a reference to another sub_match, i.e. the other one of these guys
• s — a reference to a string you're comparing against
• c — a pointer to a null-terminated character sequence of the underlying value_type, the thing you're comparing against

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🌸 Return value 🌸

Here's the vibe check, spelled out in numbers:

• less than zero if this sub_match is less than the other character sequence
• zero if both underlying character sequences are equal (slay, a match 💖)
• greater than zero if this sub_match is greater than the other character sequence

So it's the classic three-way situation — negative, zero, positive. No cap.

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🦋 Example 🦋

This section is incomplete
Reason: no example

😭 not me finding out the example section is literally empty. Bestie... the docs said "no example" and I felt that. If you want, go write one — the page is begging for it 🙈

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🧚 See also 🧚

• compare — compares two strings (public member function of std::basic_string<CharT,Traits,Allocator>)
• str — converts to the underlying string type
• operator string_type — converts to the underlying string type (public member function)
• operator==, operator!=, operator<, operator<=, operator>, operator>=, operator<=> (removed in C++20) — compares a sub_match with another sub_match, a string, or a character (function template) — and note that <=> is the C++20 one 💅

Also, just so nobody comes for me: this page is filed under the category Todo no example. Not a vibe, but we move.

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Alright, that's the whole thing! This page came to you from cppreference.com, dated 2024.06.10 — big love to them for the source and the version, and go off, bestie, you now understand std::sub_match::compare 💜🔥👑