add docs for packed enum

This commit is contained in:
Andrew Kelley 2018-04-06 19:14:49 -04:00
parent fef06f2142
commit eae355d771

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@ -1947,8 +1947,24 @@ const Foo = extern enum { A, B, C };
export fn entry(foo: Foo) void { }
{#code_end#}
{#header_close#}
<p>TODO packed enum</p>
{#see_also|@memberName|@memberCount|@tagName#}
{#header_open|packed enum#}
<p>By default, the size of enums is not guaranteed.</p>
<p><code>packed enum</code> causes the size of the enum to be the same as the size of the integer tag type
of the enum:</p>
{#code_begin|test#}
const std = @import("std");
test "packed enum" {
const Number = packed enum(u8) {
One,
Two,
Three,
};
std.debug.assert(@sizeOf(Number) == @sizeOf(u8));
}
{#code_end#}
{#header_close#}
{#see_also|@memberName|@memberCount|@tagName|@sizeOf#}
{#header_close#}
{#header_open|union#}
{#code_begin|test|union#}