absl/random/seed_gen_exception.h

0001 // Copyright 2017 The Abseil Authors.
0002 //
0003 // Licensed under the Apache License, Version 2.0 (the "License");
0004 // you may not use this file except in compliance with the License.
0005 // You may obtain a copy of the License at
0006 //
0007 //      https://www.apache.org/licenses/LICENSE-2.0
0008 //
0009 // Unless required by applicable law or agreed to in writing, software
0010 // distributed under the License is distributed on an "AS IS" BASIS,
0011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0012 // See the License for the specific language governing permissions and
0013 // limitations under the License.
0014 //
0015 // -----------------------------------------------------------------------------
0016 // File: seed_gen_exception.h
0017 // -----------------------------------------------------------------------------
0018 //
0019 // This header defines an exception class which may be thrown if unpredictable
0020 // events prevent the derivation of suitable seed-material for constructing a
0021 // bit generator conforming to [rand.req.urng] (eg. entropy cannot be read from
0022 // /dev/urandom on a Unix-based system).
0023 //
0024 // Note: if exceptions are disabled, `std::terminate()` is called instead.
0025
0026 #ifndef ABSL_RANDOM_SEED_GEN_EXCEPTION_H_
0027 #define ABSL_RANDOM_SEED_GEN_EXCEPTION_H_
0028
0029 #include <exception>
0030
0031 #include "absl/base/config.h"
0032
0033 namespace absl {
0034 ABSL_NAMESPACE_BEGIN
0035
0036 //------------------------------------------------------------------------------
0037 // SeedGenException
0038 //------------------------------------------------------------------------------
0039 class SeedGenException : public std::exception {
0040  public:
0041   SeedGenException() = default;
0042   ~SeedGenException() override;
0043   const char* what() const noexcept override;
0044 };
0045
0046 namespace random_internal {
0047
0048 // throw delegator
0049 [[noreturn]] void ThrowSeedGenException();
0050
0051 }  // namespace random_internal
0052 ABSL_NAMESPACE_END
0053 }  // namespace absl
0054
0055 #endif  // ABSL_RANDOM_SEED_GEN_EXCEPTION_H_