[Issue 18470] New: std.algorithm.splitter has frame access problems for custom preds

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18470

          Issue ID: 18470
           Summary: std.algorithm.splitter has frame access problems for
                    custom preds
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: phobos
          Assignee: nobody at puremagic.com
          Reporter: greensunny12 at gmail.com

This isn't an issue for the string binaryFuns as used in the examples, but
their lambda variants fail:

---
void main()
{
    import std.algorithm;

    auto w = [[0], [1], [2]];
    assert(w.splitter!"a.front == b"(1).equal([[[0]], [[2]]]));

    assert(w.splitter!((a, b) => a.front == b)(1).equal([[[0]], [[2]]])); //
fails
}
---

---
onlineapp.d(8): Error: template std.algorithm.iteration.splitter cannot deduce
function from argument types !((a, b) => a.front == b)(int[][], int),
candidates are:
/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/iteration.d(3695):       
std.algorithm.iteration.splitter(alias pred = "a == b", Range, Separator)(Range
r, Separator s) if (is(typeof(binaryFun!pred(r.front, s)) : bool) &&
(hasSlicing!Range && hasLength!Range || isNarrowString!Range))
/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/iteration.d(4000):       
std.algorithm.iteration.splitter(alias pred = "a == b", Range, Separator)(Range
r, Separator s) if (is(typeof(binaryFun!pred(r.front, s.front)) : bool) &&
(hasSlicing!Range || isNarrowString!Range) && isForwardRange!Separator &&
(hasLength!Separator || isNarrowString!Separator))
/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/iteration.d(4264):       
std.algorithm.iteration.splitter(alias isTerminator, Range)(Range input) if
(isForwardRange!Range && is(typeof(unaryFun!isTerminator(input.front))))
/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/iteration.d(4510):       
std.algorithm.iteration.splitter(C)(C[] s) if (isSomeChar!C)
----


---
void main()
{
    import std.algorithm;
    import std.ascii : toLower;

    assert("abXcdxef".splitter!"a.toLower == b"('x').equal(["ab", "cd",
"ef"]));
    assert("abXcdxef".splitter!((a, b) => a.toLower == b)('x').equal(["ab",
"cd", "ef"]));
}
---


---
/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/iteration.d(3726): Error:
static function onlineapp.main.splitter!((a, b) => a.toLower == b, string,
char).splitter.Result.lastIndexOf cannot access frame of function D main
/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/iteration.d(3764): Error:
function onlineapp.main.splitter!((a, b) => a.toLower == b, string,
char).splitter.Result.front cannot access frame of function D main
onlineapp.d(8): Error: template instance onlineapp.main.splitter!((a, b) =>
a.toLower == b, string, char) error instantiating
---

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