What is std::format?

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Accepted Answer

**std::format** — safe string formatting (C++20). ```cpp #include std::string s = std::format("Hello, {}! You are {}.", "Alice", 30); // Formatting specifiers std::cout << std::format("{:.2f}", 3.14159); // 3.14 std::cout << std::format("{:10}", "hi"); // " hi" std::cout << std::format("{:05d}", 42); // 00042 std::cout << std::format("{:#x}", 255); // 0xff ``` **vs printf/snprintf:** - Type-safe (no format string mismatches) - Extensible (custom formatters) - Compile-time format string checking - Better performance **Custom formatters:** ```cpp template <> struct std::formatter { auto format(const MyType& v, auto& ctx) { return std::format_to(ctx.out(), "({},{})", v.x, v.y); } }; ```

C++: What is std::format?