mirror of
https://github.com/monero-project/monero.git
synced 2024-12-04 23:51:08 +02:00
common: add va_args.h
This PR is upstreaming changes in the Seraphis lib here: https://github.com/UkoeHB/monero/pull/39. This header adds a macro `VA_ARGS_COMMAPREFIX` which, when passed `__VA_ARGS__`, expands to `, __VA_ARGS__` unless the length of `__VA_ARGS__` is 0, in which case it expands to nothing. This macro is useful for passing/declaring optional function arguments.
This commit is contained in:
parent
0db9e74223
commit
b2c59c498c
45
src/common/va_args.h
Normal file
45
src/common/va_args.h
Normal file
@ -0,0 +1,45 @@
|
||||
// Copyright (c) 2024, The Monero Project
|
||||
//
|
||||
// All rights reserved.
|
||||
//
|
||||
// Redistribution and use in source and binary forms, with or without modification, are
|
||||
// permitted provided that the following conditions are met:
|
||||
//
|
||||
// 1. Redistributions of source code must retain the above copyright notice, this list of
|
||||
// conditions and the following disclaimer.
|
||||
//
|
||||
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
|
||||
// of conditions and the following disclaimer in the documentation and/or other
|
||||
// materials provided with the distribution.
|
||||
//
|
||||
// 3. Neither the name of the copyright holder nor the names of its contributors may be
|
||||
// used to endorse or promote products derived from this software without specific
|
||||
// prior written permission.
|
||||
//
|
||||
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
|
||||
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
||||
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
|
||||
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
||||
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
||||
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
||||
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
||||
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
|
||||
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
|
||||
#pragma once
|
||||
|
||||
// Check for __VA_OPT__ support
|
||||
// Apdated from cpplearner's StackOverflow answer: https://stackoverflow.com/a/48045656
|
||||
#define PP_THIRD_ARG(a,b,c,...) c
|
||||
#define VA_OPT_SUPPORTED_I(...) PP_THIRD_ARG(__VA_OPT__(,),true,false,)
|
||||
#define VA_OPT_SUPPORTED VA_OPT_SUPPORTED_I(?)
|
||||
|
||||
// VA_ARGS_COMMAPREFIX(): VA_ARGS_COMMAPREFIX(__VA_ARGS__) expands to __VA_ARGS__ with a comma in
|
||||
// front if more than one argument, else nothing.
|
||||
// If __VA_OPT__ supported, use that. Else, use GCC's ,## hack
|
||||
#if VA_OPT_SUPPORTED
|
||||
# define VA_ARGS_COMMAPREFIX(...) __VA_OPT__(,) __VA_ARGS__
|
||||
#else
|
||||
# define VA_ARGS_COMMAPREFIX(...) , ## __VA_ARGS__
|
||||
#endif
|
||||
|
Loading…
Reference in New Issue
Block a user