On Sunday, 12 March 2023 at 15:09:45 UTC, Salih Dincer wrote:
Hi,
[...]
// A, we can get its to guarantee us that parameters
// won't change:
auto inConst(T)(T a, const T b) // const
{ // it's not needed --^ but ^-- why can't this be used
Well you got the great answers to your questions already but I
like to add a comment that is that
**`const` parameters without `ref` are really moot.**
I whish at least that they could give the guarantee to be rvalues
(i.e have no address) but this is actually not the case. All the
D compilers will actually copy `const` parameters to locals,
making them lvalues, unless optimizations are requested(1).
See codegen : https://godbolt.org/z/vev1PGWh3.
This brings the idea that maybe a `rvalue` storage class could be
added to the language.
(1): Actually DMD does not drop the copy **at all**, even with -O.
