Bill Baxter wrote:
Currently this doesn't work, because the CTFE function doesn't "know"
that it's running compile-time:
int templ_incr(int x)() {
return x+1;
}
int ctfe_incr(int x) {
return templ_incr!(x);
}
Seems common to write a function that you know is only intended to be
used compile-time.
But it can't compile because the compiler doesn't know you only plan
to call it at compile-time.
Is something version(__ctfe) might help with? E.g.
version(__ctfe) {
// only allow cfte_incr to be called at compile-time so it can use templates
int ctfe_incr(int x) {
return templ_incr!(x);
}
}
No. Here's the only functionality you'll get. This works by exploiting
bug 1330. It's inefficient: the inCTFE function gets called all the
time. Should just be a bool value, which will be constant-folded away.
Otherwise, it's the same as this:
// true if evaluated in CTFE, false if called at runtime.
bool inCTFE()
{
int [1] x = [1];
int [] y = x;
y[0] = 2;
return x[0]!=2;
}
static assert(inCTFE());
void main()
{
assert(!inCTFE());
}
