It's pretty lame that ISO C doesn't provide integer-to-string conversion that does not go through a printf-family formatter, so that programs are still rolling

It's pretty lame that ISO C doesn't provide integer-to-string conversion that does not go through a printf-family formatter, so that programs are still rolling their own "itoa" as the calendar turns to 2025. Format strings are compilable in principle, so that: snprintf(buf, sizeof buf, "%ld", long_value); can just turn into some compiler-specific run-time function. The compiler also can tell when the buffer is obviously large enough to hold any possible value, and use a function that doesn't need the size. How common is that, though? Common Lisp's format function can accept a function instead of a format string. The arguments are passed to that function and it is assumed to do the job: (format t (lambda (...) ...) args ...) There is a macro called formatter which takes a format string, and compiles it to such a function. [8]> (format t "~1,05f" pi) 3.14159 NIL [9]> (format t "~10,5f" pi) 3.14159 NIL [10]> (format t (formatter "~10,5f") pi) 3.14159 NIL [11]> (macroexpand '(formatter "~10,5F")) #'(LAMBDA (STREAM #:ARG3345 &REST #:ARGS3342) (DECLARE (IGNORABLE STREAM)) (LET ((SYSTEM::*FORMAT-CS* NIL)) (DECLARE (IGNORABLE #:ARG3345 #:ARGS3342)) (SYSTEM::DO-FORMAT-FIXED-FLOAT STREAM NIL NIL 10 5 NIL NIL NIL #:ARG3345) #:ARGS3342)) ; T In this implementation, formatter takes "~10,5f" and spins it into a (system::do-format-fixed-float ...) call where the field width and precision arguments are constants. Just the stream and numeric argument are passed in, along with a bunch of other arguments that are defaulted to nil. I think CL implementations are allowed to apply formatter implicitly, which would make sense at least in code compiled for speed. Just think: this stuff existed before there was a GNU C compiler. It was a huge progress when it started diagnosing mismatches between format strings literal and printf arguments.