1 // Copyright 2017 The Abseil Authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 // ----------------------------------------------------------------------------- 16 // File: seed_gen_exception.h 17 // ----------------------------------------------------------------------------- 18 // 19 // This header defines an exception class which may be thrown if unpredictable 20 // events prevent the derivation of suitable seed-material for constructing a 21 // bit generator conforming to [rand.req.urng] (eg. entropy cannot be read from 22 // /dev/urandom on a Unix-based system). 23 // 24 // Note: if exceptions are disabled, `std::terminate()` is called instead. 25 26 #ifndef ABSL_RANDOM_SEED_GEN_EXCEPTION_H_ 27 #define ABSL_RANDOM_SEED_GEN_EXCEPTION_H_ 28 29 #include <exception> 30 31 #include "absl/base/config.h" 32 33 namespace absl { 34 ABSL_NAMESPACE_BEGIN 35 36 //------------------------------------------------------------------------------ 37 // SeedGenException 38 //------------------------------------------------------------------------------ 39 class SeedGenException : public std::exception { 40 public: 41 SeedGenException() = default; 42 ~SeedGenException() override; 43 const char* what() const noexcept override; 44 }; 45 46 namespace random_internal { 47 48 // throw delegator 49 [[noreturn]] void ThrowSeedGenException(); 50 51 } // namespace random_internal 52 ABSL_NAMESPACE_END 53 } // namespace absl 54 55 #endif // ABSL_RANDOM_SEED_GEN_EXCEPTION_H_ 56