metadataString

pub fn metadataString(self: *Builder, bytes: []const u8) Allocator.Error!Metadata.String {
    assert(bytes.len > 0);
    try self.metadata_string_bytes.ensureUnusedCapacity(self.gpa, bytes.len);
    try self.metadata_string_indices.ensureUnusedCapacity(self.gpa, 1);
    try self.metadata_string_map.ensureUnusedCapacity(self.gpa, 1);

    const gop = self.metadata_string_map.getOrPutAssumeCapacityAdapted(
        bytes,
        Metadata.String.Adapter{ .builder = self },
    );
    if (!gop.found_existing) {
        self.metadata_string_bytes.appendSliceAssumeCapacity(bytes);
        self.metadata_string_indices.appendAssumeCapacity(
            @intCast(self.metadata_string_bytes.items.len),
        );
    }
    return @fromBackingInt(@intCast(gop.index));
}