[Issue 13683] More precise error message for wrong lambda

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=13683

Nick Treleaven <nick at geany.org> changed:

           What    |Removed                     |Added
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                 CC|                            |nick at geany.org
          Component|dmd                         |phobos

--- Comment #1 from Nick Treleaven <nick at geany.org> ---
Changing to phobos bug because `all`'s constraint uses:

is(typeof(unaryFun!pred(range.front)))

Instead this could be made a static assert, so at least the user can be
informed that the predicate is not callable with Foo.

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