Tag

Source
Implementation

pub fn Tag(comptime T: type) type {
    return switch (@typeInfo(T)) {
        .@"enum" => |info| info.tag_type,
        .@"union" => |info| info.tag_type orelse @compileError(@typeName(T) ++ " has no tag type"),
        else => @compileError("expected enum or union type, found '" ++ @typeName(T) ++ "'"),
    };
}