***** Description: *****

The following code will not compile with DMD64 D Compiler v2.055 (from github):

----------
auto func = function double(double x) {return x;}; // OK

struct Foo {double function(double) func;}
auto f1 = Foo(function double(double x) {return x;}); // Error

void main()
{
    auto f2 = Foo(function double(double x) {return x;}); // OK
}
----------
Error: non-constant expression cast(double function(double))function pure nothrow @safe double(double x)
----------

Compilation fails only if the initializer is placed outside main function.


***** Suspecting: *****

This can be related to Issue 2634 (fixed).