• d-bugmail puremagic.com (36/36) Dec 20 2022 https://issues.dlang.org/show_bug.cgi?id=23571

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=23571

          Issue ID: 23571
           Summary: Discussion of manifest constants in enum documentation
                    is confusing at best
           Product: D
           Version: D2
          Hardware: x86_64
                OS: FreeBSD
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dlang.org
          Assignee: nobody puremagic.com
          Reporter: donaldcallen1942 icloud.com

Section 17.3 of the Language documentation discusses manifest constants.

Subsection 17.3.1 describes anonymous enums having only one value.
Subsection 17.3.2 defines manifest constants.

The effect is to imply that only anonymous enums having only one value are
manifest constants. This is not true.

import std.stdio;
import std.format;

enum Foo {
    bar = 1,
    bletch = 2
}

int main(string[] args)
{
    writefln("%x", &Foo.bar);
    return 0;
}

Compiling this with dmd 2.101.0 produces

dca giovanni:/tmp$ dmd test.d
test.d(11): Error: manifest constant `bar` cannot be modified

All enums are manifest constants, per the definition in 17.3.2. The
documentation should make this clear and doesn't.

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