Bug 23243 – std.range.isInfinite should accept ranges with non-static empty methods

As of DMD 2.100.0, the following program fails to compile: --- import std.range.primitives; struct R { int front() { return 42; } bool empty() { return false; } void popFront() {} } static assert(isInputRange!R); // ok enum e = R().empty; // ok static assert(isInfinite!R); // fails --- Since R is an input range whose .empty property evaluates to false at compile time, it should be accepted as an infinite range. This issue blocks issue 23242.

On second thought, this is not possible, because (1) we cannot check the return value of .empty for all possible instances of R, and (2) even if .empty returns false for every instance tested, we can never be sure it will not return true for some other instance we did not test.