Printf library suggestion

From: Aaron Graham (AGraham_at_[hidden])
Date: 2025-04-22 22:27:19

I'd like to gauge the interest in adding the following library to boost:
https://github.com/rokudev/rostd/blob/main/include/rostd/printx.hpp

It's a simple library that checks and rewrites the format string at compile
time in order to fortify it for use with printf, leaving the object code
with only a call to the underlying C-standard printf-family function.

It's a single header and requires C++20 or above (for cNTTP support).
It contains these four functions: printf, sprintf, snprintf, fprintf

These functions are used like so:

    printf<"Hello %s\n">("World!");

    char buf[20];
    sprintf<"Hello %s\n">(buf, "World!"); // yes, it's safe

    char buf[20];
    snprintf<"Hello %s\n">(buf, sizeof buf, "World!");

    fprintf<"Hello %s\n">(file, "World!");

Features/rationale:

* It provides old-style printf (supports all standard printf specifiers).
* Fully type-safe. No format string attacks. Issues are found at compile time.
* Length modifiers are deduced; these format strings are portable.
  (No PRIu64 inttypes stuff needed anymore, just use %u)
* Adds %? format specifier (print whatever type is there).
* Compiles to std::printf (much smaller object code than std::format).
* Provides a way for developers to easily adapt this printf formatting
  capability to their own functions (logging, etc.)

More detailed rationale is here:
https://github.com/rokudev/rostd/blob/main/doc/printx.adoc