On Wednesday, 7 May 2014 at 16:04:39 UTC, Nordlöw wrote:
void foo(T)(InputRange!T range);
Update:
Ahh, it seems this syntax is currently accepted by DMD. Should
it be?
Original function:
import std.range: isInputRange;
bool allEqual(R)(R range) @safe pure nothrow if (isInputRange!R)
{
import std.algorithm: findAdjacent;
import std.range: empty;
return range.findAdjacent!("a != b").empty;
}
unittest { assert([11, 11].allEqual); }
unittest { assert(![11, 12].allEqual); }
unittest { int[] x; assert(x.allEqual); }
compiles.
New function:
import std.range: InputRange;
bool allEqual_(T)(InputRange!T range) @safe pure nothrow
{
import std.algorithm: findAdjacent;
import std.range: empty;
return range.findAdjacent!("a != b").empty;
}
unittest { assert([11, 11].allEqual_); }
unittest { assert(![11, 12].allEqual_); }
unittest { int[] x; assert(x.allEqual_); }
fails as
algorithm_ex.d(190,27): Error: template algorithm_ex.allEqual_
cannot deduce function from argument types !()(int[]),
candidates are:
algorithm_ex.d(184,6):
algorithm_ex.allEqual_(T)(InputRange!T range)
algorithm_ex.d(191,28): Error: template algorithm_ex.allEqual_
cannot deduce function from argument types !()(int[]),
candidates are:
algorithm_ex.d(184,6):
algorithm_ex.allEqual_(T)(InputRange!T range)
algorithm_ex.d(192,29): Error: template algorithm_ex.allEqual_
cannot deduce function from argument types !()(int[]),
candidates are:
algorithm_ex.d(184,6):
algorithm_ex.allEqual_(T)(InputRange!T range)
std.range.InputRange is an interface template. int[] is not
implicitly convertable to InputRange!(T[]), which is in fact an
interface to a range with element type int[] (not int)
std.range.isInputRange and std.range.InputRange are unrelated
except that the latter satisfies the former.
