On Sunday, 25 January 2015 at 18:59:04 UTC, ketmar wrote:
auto x2 = (x>>4) | (x<<4); // swap nibbles - but result in an
int!!!!!
this is true for C and C++ too, as all three languages doing
"integer
promotion". the only difference is that D forbids potentially
lossy
assigns.
you best bet is to not use `auto`, but specify required type
explicitly.
or use ints/uints and cast to bytes only when it is necessary.
in normal assignments I never use auto - it's not simpler than
writing the type explicit but later makes it more complicated to
see what type it is.
But in a function you need the cast anyway:
ubyte swapNibbles(ubyte x) { return (x>>4) | (x>>4); } //
compiler not happy
or if you index with a long, even after explicit check:
int foo(ulong x)
{
int[10] a;
return (x < 10) ? a[x] : 0; // cannot index with long
}
So there are plenty of places in D where cast is necessary but
should not be.
I think both of above cases should be safe without cast, and
enhancing the compilerr that it can handle these cases is more
important than a iota!"[]".
Until then I prefer paramCast!fn, because this is more flexible
than the iota extension and my code is full of casts anyway.
