Implicit conversion in initializers doesn't work for subtypes

[dlangBugzillaToGithub]

Andrej Mitrovic (@AndrejMitrovic) reported this on 2013-04-29T03:30:47Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=10006

Description

-----
struct S
{
    float value = 0.0;
    alias value this;
}

float f = 250.0;  // ok
S s = 250.0;  // ng

void main() { }
-----

Error: cannot implicitly convert expression (250.000) of type double to S

I think the above should work.

[dlangBugzillaToGithub]

andrej.mitrovich (@AndrejMitrovic) commented on 2013-04-29T03:32:28Z

This does give me an idea for a DIP:

struct S
{
    float value = 0.0;
    alias value this;

    // called only when a *literal* is provided
    this(enum double val) { }
}

This would enable creating custom implicit conversions when initializing a struct with a literal of some sort.