On Sunday, 31 December 2017 at 13:32:03 UTC, aliak wrote:
So it seems it tries to compile the statements below the check
on V.length even though it's guaranteed to be true and there's
a return statement inside the if.
Yeah, static if includes or excludes code independently at
compile time.
So what you wrote there would be like, assuming the first to
static ifs pass:
auto concat(R, V...)(R range, V values) if (isInputRange!R) {
import std.range: chain, ElementType;
return range;
return range.chain(values[0]).concat(values[1..$]);
}
The code is still there, even if it isn't reached due to an early
return, and thus still must compile.
Using else static if means it won't be generated.