usage.h (1513B)
1 // 2 // Copyright 2019 The Abseil Authors. 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // https://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 16 #ifndef ABSL_FLAGS_USAGE_H_ 17 #define ABSL_FLAGS_USAGE_H_ 18 19 #include "absl/base/config.h" 20 #include "absl/strings/string_view.h" 21 22 // -------------------------------------------------------------------- 23 // Usage reporting interfaces 24 25 namespace absl { 26 ABSL_NAMESPACE_BEGIN 27 28 // Sets the "usage" message to be used by help reporting routines. 29 // For example: 30 // absl::SetProgramUsageMessage( 31 // absl::StrCat("This program does nothing. Sample usage:\n", argv[0], 32 // " <uselessarg1> <uselessarg2>")); 33 // Do not include commandline flags in the usage: we do that for you! 34 // Note: Calling SetProgramUsageMessage twice will trigger a call to std::exit. 35 void SetProgramUsageMessage(absl::string_view new_usage_message); 36 37 // Returns the usage message set by SetProgramUsageMessage(). 38 absl::string_view ProgramUsageMessage(); 39 40 ABSL_NAMESPACE_END 41 } // namespace absl 42 43 #endif // ABSL_FLAGS_USAGE_H_