POD struct not equivalent to primitive type in comparison

[dlangBugzillaToGithub]

anonymous4 reported this on 2017-09-28T10:49:26Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=17864

CC List

• Duncan Paterson
• RazvanN

Description

struct A { int a; }
void g()
{
	shared A a;
	A b;
	a=b; //converts
	assert(a==b); //fail
}
Error: incompatible types for ((a) is (b)): 'shared(A)' and 'A'

Works for immutable. Is it an oversight?

[dlangBugzillaToGithub]

dunkyp commented on 2017-10-02T15:36:58Z

I don't think this is an oversight. The table at https://dlang.org/spec/const3.html in section 18.11 says that shared cannot be implicitly converted to mutable. The same code as yours with b marked immutable works. I do think this behaviour is a little surprising.

[dlangBugzillaToGithub]

razvan.nitu1305 commented on 2018-06-14T13:41:46Z

PR: https://github.com/dlang/dmd/pull/8358