Comment # 3 on bug 140 from Johannes Pfau

Reduced:

test.d
----------------------------------------------------
import xtd.array;

int main()
{
    void[] a = [];
    return (FilterResult!(void[])(a)).empty;
}

struct FilterResult(Range)
{
    Range _input;

    @property empty() { return xtd.array.empty(_input); }
}
----------------------------------------------------

xtd/array.d
----------------------------------------------------
import gcc.attribute;

@attribute("forceinline") @property empty(T)(in T[] a)
{
    return !a.length;
}
----------------------------------------------------

gdc test.d -finline
----------------------------------------------------
test.d: In member function 'empty':
xtd/array.d:3: error: inlining failed in call to always_inline 'empty':
mismatched arguments
test.d:14: error: called from here
----------------------------------------------------


Merging array.d/test.d leads to a different error:
test.d
----------------------------------------------------
import gcc.attribute;

@attribute("forceinline") @property empty2(T)(in T[] a)
{
    return !a.length;
}


int main()
{
    void[] a = [];
    return (FilterResult!(void[])(a)).empty;
}

struct FilterResult(Range)
{
    Range _input;

    @property empty() { return empty2(_input); }
}
----------------------------------------------------

gdc test.d -finline
----------------------------------------------------
cc1d: /build/gdc/src/gcc-4.9.0/gcc/d/dfrontend/interpret.c:676: void
FuncDeclaration::ctfeCompile(): Assertion `semanticRun == PASSsemantic3done'
failed.
test.d: In member function 'empty':
test.d:18: internal compiler error: Aborted
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://bugs.archlinux.org/> for instructions.
----------------------------------------------------

This error vanishes if the forceinline attribute is removed.