Acts/Utilities/ThrowAssert.hpp

0001 // This file is part of the ACTS project.
0002 //
0003 // Copyright (C) 2016 CERN for the benefit of the ACTS project
0004 //
0005 // This Source Code Form is subject to the terms of the Mozilla Public
0006 // License, v. 2.0. If a copy of the MPL was not distributed with this
0007 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
0008
0009 #pragma once
0010
0011 #include <exception>
0012 #include <iostream>
0013 #include <sstream>
0014 #include <string>
0015
0016 namespace Acts {
0017 /// @brief Exception type for assertion failures
0018 /// This class captures the information available to the throw_assert macro
0019 class AssertionFailureException : public std::exception {
0020  public:
0021   /// @brief Class which allows to use the << operator to assemble a string
0022   class StreamFormatter {
0023    private:
0024     std::ostringstream stream;
0025
0026    public:
0027     /// @brief Converts to string
0028     explicit operator std::string() const { return stream.str(); }
0029
0030     /// @brief Stream operator which takes everything and forwards
0031     ///        it to the stringstream.
0032     /// @tparam T type of anything
0033     /// @param value const ref to anything
0034     /// @return Reference to this StreamFormatter
0035     template <typename T>
0036     StreamFormatter& operator<<(const T& value) {
0037       stream << value;
0038       return *this;
0039     }
0040   };
0041
0042   /// @brief Construct an assertion failure exception, captures macro info
0043   /// @param expression The expression being asserted
0044   /// @param file The current file
0045   /// @param line The current line
0046   /// @param msg The message to print if assertion fails
0047   AssertionFailureException(const std::string& expression,
0048                             const std::string& file, int line,
0049                             const std::string& msg) {
0050     std::ostringstream os;
0051
0052     if (!msg.empty()) {
0053       os << msg << ": ";
0054     }
0055
0056     os << "Assertion '" << expression << "'";
0057
0058     os << " failed in file '" << file << "' line " << line;
0059     report = os.str();
0060   }
0061
0062   /// The assertion message
0063   /// @return C-string containing the assertion failure message
0064   const char* what() const throw() override { return report.c_str(); }
0065
0066  private:
0067   std::string report;
0068 };
0069
0070 }  // namespace Acts
0071
0072 #define throw_assert(EXPRESSION, MESSAGE)                                      \
0073   do {                                                                         \
0074     if (!(EXPRESSION)) {                                                       \
0075       throw Acts::AssertionFailureException(                                   \
0076           #EXPRESSION, __FILE__, __LINE__,                                     \
0077           static_cast<std::string>(                                            \
0078               Acts::AssertionFailureException::StreamFormatter() << MESSAGE)); \
0079     }                                                                          \
0080   } while (0)