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Diffstat (limited to 'src/util/overloaded.h')
-rw-r--r-- | src/util/overloaded.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/util/overloaded.h b/src/util/overloaded.h new file mode 100644 index 0000000000..6be7453f81 --- /dev/null +++ b/src/util/overloaded.h @@ -0,0 +1,22 @@ +// Copyright (c) 2021 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_UTIL_OVERLOADED_H +#define BITCOIN_UTIL_OVERLOADED_H + +namespace util { +//! Overloaded helper for std::visit. This helper and std::visit in general are +//! useful to write code that switches on a variant type. Unlike if/else-if and +//! switch/case statements, std::visit will trigger compile errors if there are +//! unhandled cases. +//! +//! Implementation comes from and example usage can be found at +//! https://en.cppreference.com/w/cpp/utility/variant/visit#Example +template<class... Ts> struct Overloaded : Ts... { using Ts::operator()...; }; + +//! Explicit deduction guide (not needed as of C++20) +template<class... Ts> Overloaded(Ts...) -> Overloaded<Ts...>; +} // namespace util + +#endif // BITCOIN_UTIL_OVERLOADED_H |