On 07.08.2017 10:01, Shachar Shemesh wrote:
It is often desired to have a struct with an extra parameter. The common
way to do this is like so:
struct S(T) {
T param;
void initialize(T param) {
this.param = param;
// Other stuff
}
}
The problem is what happens when the param is optional. The common way
to do this is to set T to void. This results in the following code:
struct S(T) {
enum HasParam = !is(T == void);
static if( HasParam ) {
T param;
}
static if( HasParam ) {
void initialize(T param) {
this.param = param;
// Other stuff
}
} else {
void initialize() {
// Same other stuff as above!
}
}
}
This is both tedious and error prone. Is there a cleaner way of doing this?
...
struct S(T...) {
T param;
void initialize(T param) {
this.param = param;
// Other stuff
}
}
Then, use S!() instead of S!void.
Just as an unrealistic fantasy, if the following code was legal, the
problem would be resolved on its own:
void func(void p) {
void param;
param = p;
return param;
}
Of course, that code has its own set of problems, and I'm not really
suggesting that change.
Shachar
The only reason this code is problematic is that void.sizeof == 1.