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Programming-Idioms

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  • C++

Idiom #96 Check string prefix

Set the boolean b to true if string s starts with prefix prefix, false otherwise.

Are the first characters of s equal to this prefix?
#include <string>
std::string prefix = "something";
bool b = s.compare(0, prefix.size(), prefix) == 0;

empty prefix is true
#include <string>
bool b = s.starts_with(prefix);

C++20
with Ada.Strings.Fixed;
B := Ada.Strings.Fixed.Index (S, Prefix) = S'First;

New implementation...