[Issue 15641] New: std.typecons.Proxy doesn't work when destructor is not nothrow

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15641

          Issue ID: 15641
           Summary: std.typecons.Proxy doesn't work when destructor is not
                    nothrow
           Product: D
           Version: D2
          Hardware: x86_64
                OS: All
            Status: NEW
          Severity: regression
          Priority: P1
         Component: phobos
          Assignee: nobody at puremagic.com
          Reporter: saurabh.das at gmail.com

This code:

struct A
{
    import std.stdio;
    File f;
}

struct B
{
    A a;

    import std.typecons;
    mixin Proxy!a;
}

rdmd proxytest.d:
/Library/D/dmd/src/phobos/std/typecons.d(5055): Error: 'proxytest.A.~this' is
not nothrow
/Library/D/dmd/src/phobos/std/typecons.d(5050): Error: function
'proxytest.B.Proxy!(a).toHash' is nothrow yet may throw
Failed: ["dmd", "-v", "-o-", "proxytest.d", "-I."]


Marc Schütz investigated and found:
It used to work in 2.066.1; bisecting points to this PR:
https://github.com/D-Programming-Language/phobos/pull/3043

When bisecting between 2.066 and 2.067, there are other candidates:
https://github.com/D-Programming-Language/phobos/pull/3042
https://github.com/D-Programming-Language/dmd/pull/4459
https://github.com/D-Programming-Language/druntime/pull/1188

Unlikely:
https://github.com/D-Programming-Language/phobos/pull/3001
https://github.com/D-Programming-Language/phobos/pull/3043
https://github.com/D-Programming-Language/dmd/pull/4452
https://github.com/D-Programming-Language/dmd/pull/4463


Discussion on the forum:
http://forum.dlang.org/post/cmgxsjkrcmqegywsbrxd@forum.dlang.org

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