Bug 8570 – Tuples without named fields should implicitly convert to tuples with named fields when returned from a function

Currently, this compiles: void bar( ) { Tuple!( int, "a", float, "b" ) t = tuple( 1, 2.0 ); } And this does not: Tuple!( int, "a", float, "b" ) foo( ) { return tuple( 1, 2.0 ); } Ref. discussion: http://forum.dlang.org/thread/[email protected]?page=8#post-jul0qv:242l9d:241:40digitalmars.com

*** Issue 8970 has been marked as a duplicate of this issue. ***

Reduced: struct S { this(int) {} } void bar() { S s = 5; } S foo() { return 5; } The first is an initialization / assignment; the second is an implicit conversion. Currently D does not allow defining implicit conversions to arbitrary types (closest is alias this, but it can alias only specific types). Providing some way for types to do implicit conversions to arbitrary other types is a much bigger discussion outside of the scope of this issue.