mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-10-01 20:06:01 +01:00
Dana JansensandRichard Smith
b24944bfba
We use CARBON_KIND_SWITCH for handling the output of TypeIterator in the TypeStructureBuilder Here is how the errors look when it is misused: - If you don't cover ever type in the variant with a case ``` Enumeration value 'VariantTypeT1NotHandledInSwitch' not handled in switch ``` Is attached to the CARBON_KIND_SWITCH() usage, the `T1` being a 0-based index into the std::variant's type list, indicating which type was missed. - If you have a case for a type that is not in the variant ``` In template: constraints not satisfied for class template 'ValidCaseType' [with T = char] ... bunch of instantiation stuff ... kind_switch.h(124, 12): Because 'char' does not satisfy 'TypeFoundInVariant' ``` Where `char` was the type I put in the `CARBON_KIND` macro, which was not in the variant. - If you have too many types in your variant (currently > 12) ``` In template: static assertion failed due to requirement 'sizeof...(Ts) <= 12': CARBON_KIND_SWITCH supports std::variant with up to 12 types. Add more if needed. ``` Is attached to the CARBON_KIND_SWITCH() usage. --------- Co-authored-by: Richard Smith <richard@metafoo.co.uk>
45 lines
2.1 KiB
C
45 lines
2.1 KiB
C
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
|
|
// Exceptions. See /LICENSE for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
|
|
#ifndef CARBON_TOOLCHAIN_BASE_FOR_EACH_MACRO_H_
|
|
#define CARBON_TOOLCHAIN_BASE_FOR_EACH_MACRO_H_
|
|
|
|
/// CARBON_FOR_EACH() will apply `macro` to each argument in the variadic
|
|
/// argument list, putting the output of `sep()` between each one.
|
|
///
|
|
/// The `sep` should be a function macro that returns a separator. Premade
|
|
/// separataors are provided as CARBON_FOR_EACH_XYZ() macros.
|
|
#define CARBON_FOR_EACH(macro, sep, ...) \
|
|
__VA_OPT__(CARBON_INTERNAL_FOR_EACH_EXPAND( \
|
|
CARBON_INTERNAL_FOR_EACH(macro, sep, __VA_ARGS__)))
|
|
|
|
#define CARBON_FOR_EACH_COMMA() ,
|
|
#define CARBON_FOR_EACH_SEMI() ;
|
|
#define CARBON_FOR_EACH_CONCAT()
|
|
|
|
// Internal helpers
|
|
|
|
#define CARBON_INTERNAL_FOR_EACH(macro, sep, a1, ...) \
|
|
macro(a1) __VA_OPT__(sep()) __VA_OPT__( \
|
|
CARBON_INTERNAL_FOR_EACH_AGAIN CARBON_INTERNAL_FOR_EACH_PARENS( \
|
|
macro, sep, __VA_ARGS__))
|
|
#define CARBON_INTERNAL_FOR_EACH_PARENS ()
|
|
#define CARBON_INTERNAL_FOR_EACH_AGAIN() CARBON_INTERNAL_FOR_EACH
|
|
|
|
#define CARBON_INTERNAL_FOR_EACH_EXPAND(...) \
|
|
CARBON_INTERNAL_FOR_EACH_EXPAND1( \
|
|
CARBON_INTERNAL_FOR_EACH_EXPAND1(CARBON_INTERNAL_FOR_EACH_EXPAND1( \
|
|
CARBON_INTERNAL_FOR_EACH_EXPAND1(__VA_ARGS__))))
|
|
#define CARBON_INTERNAL_FOR_EACH_EXPAND1(...) \
|
|
CARBON_INTERNAL_FOR_EACH_EXPAND2( \
|
|
CARBON_INTERNAL_FOR_EACH_EXPAND2(CARBON_INTERNAL_FOR_EACH_EXPAND2( \
|
|
CARBON_INTERNAL_FOR_EACH_EXPAND2(__VA_ARGS__))))
|
|
#define CARBON_INTERNAL_FOR_EACH_EXPAND2(...) \
|
|
CARBON_INTERNAL_FOR_EACH_EXPAND3( \
|
|
CARBON_INTERNAL_FOR_EACH_EXPAND3(CARBON_INTERNAL_FOR_EACH_EXPAND3( \
|
|
CARBON_INTERNAL_FOR_EACH_EXPAND3(__VA_ARGS__))))
|
|
#define CARBON_INTERNAL_FOR_EACH_EXPAND3(...) __VA_ARGS__
|
|
|
|
#endif // CARBON_TOOLCHAIN_BASE_FOR_EACH_MACRO_H_
|