std.enums.EnumArray.initDefault and std.enums.EnumMap.initFullWithDefault fail with non-exhaustive enums

[DanikVitek]

Zig Version

0.13.0

Steps to Reproduce and Observed Behavior

1. Declare a non-exhaustive sparse enum
2. Try initializing the EnumArray via init or initDefault / EnumMap via initFullWith or initFullWithDefault
3. -> compilation error similar to "no field with value '@enumFromInt(1)' in enum 'main.E'"

EnumArray code example:

const std = @import("std");

pub fn main() !void {
    const E = enum(u3) {
        A = 0,
        B = 1, // 2,
        C = 2, // 4,
        _,
    };

    const EA = std.EnumArray(E, []const u8).initDefault("default", .{
        .A = "A",
        .B = "B",
        .C = "C",
    });

    std.debug.print("{s}\n", .{EA.get(E.A)});
}

Error message:

C:\Program Files\zigup\zig\0.13.0\files\lib\std\enums.zig:1094:29: error: no field with value '@enumFromInt(3)' in enum 'main.E'
                const tag = @tagName(key);
                            ^~~~~~~~~~~~~
src\main.zig:4:15: note: declared here
    const E = enum(u3) {
              ^~~~
referenced by:
    main: src\main.zig:11:56
    callMain: C:\Program Files\zigup\zig\0.13.0\files\lib\std\start.zig:524:32

EnumMap code example:

const std = @import("std");

pub fn main() !void {
    const E = enum(u3) {
        A = 0,
        B = 1,
        C = 2,
        _,
    };

    const EM = std.EnumMap(E, []const u8).initFullWithDefault("default", .{
        .A = "A",
        .B = "B",
        .C = "C",
    });

    std.debug.print("{?s}\n", .{EM.get(E.A)});
}

Error message:

C:\Program Files\zigup\zig\0.13.0\files\lib\std\enums.zig:507:29: error: no field with value '@enumFromInt(3)' in enum 'main.E'
                const tag = @tagName(key);
                            ^~~~~~~~~~~~~
src\main.zig:4:15: note: declared here
    const E = enum(u3) {
              ^~~~
referenced by:
    main: src\main.zig:11:62
    callMain: C:\Program Files\zigup\zig\0.13.0\files\lib\std\start.zig:524:32

Expected Behavior

Successful compilation with valid behavior

[DanikVitek]

I might just not fully understand the application to the non-exhaustive enums, as they are expected to be valid for the whole range of the backing integer

[rohlem]

Seems like this was last fixed for EnumMap.init in #19309 / 8a7b04f , but the methods you mentioned are still missing the check (were probably overlooked).
If you want to experiment with master, you can find it on the ziglang download page.
I assume a PR for this would be accepted, it you want to give it a try.
(IMO it would be nicer to update the single loop instead of having a branch to two different ones, f.e. using std.enums.tagName instead of @tagName, but that's up to the implementer.)