ladybird/AK/Try.h
Andreas Kling b4d8e166d8 AK: Add a TRY(expression) macro to simplify the unwrap-or-return pattern
The way we use classes like Kernel::KResultOr<T> and AK::Result<T, E>
makes checking for errors (and short-circuiting returns) quite verbose.

This patch adds a new TRY(expression) macro that either evaluates to
the released result of the expression if successful, or returns the
error if not.

Before:

    auto foo_or_error = get_foo();
    if (foo_or_error.is_error())
        return foo_or_error.release_error();
    auto foo = foo_or_error.release_value();

After:

    auto foo = TRY(get_foo());

The macro uses a GNU C++ extension which is supported by GCC, Clang,
Intel C++, and possibly others. It's not *ideal*, but since it makes our
codebase considerably nicer, let's try(!) it out. :^)

Co-authored-by: Ali Mohammad Pur <mpfard@serenityos.org>
2021-09-05 14:08:12 +02:00

18 lines
547 B
C

/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
// NOTE: This macro works with any result type that has the expected APIs.
// It's designed with AK::Result and Kernel::KResult in mind.
#define TRY(expression) \
({ \
auto result = (expression); \
if (result.is_error()) \
return result.release_error(); \
result.release_value(); \
})