On Fri, Dec 6, 2024 at 9:12 AM Peter Dimov via Boost
The purpose of span is to replace pointer arguments. If your function takes ... void f2( unsigned char p[4] ); you use void f2( span
p );
This is quite informative, thank you. For my entire career I have avoided passing C-style arrays because of ignorance of how they work. Is it a copy? Is it just a pointer? Does the compiler know the extent? And so on. I don't like the look of function signatures which accept language arrays, because they do not quite work the same way as other types. The fixed extent span here does two things: first, it inserts a runtime
check that the extent of the passed span is >= 4. ... Since it's statically known that 0<4, 1<4, 2<4, 3<4, these accesses don't cause any asserts to be inserted.
This is a strong rationale for using a span-like type in the signatures for those implementation functions. Thanks