Merge commit '1531d6e543' as 'gitstatus'

gitstatus/src/check.h

@@ -0,0 +1,61 @@
+// Copyright 2019 Roman Perepelitsa.
+//
+// This file is part of GitStatus.
+//
+// GitStatus is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GitStatus is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GitStatus. If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef ROMKATV_GITSTATUS_CHECK_H_
+#define ROMKATV_GITSTATUS_CHECK_H_
+
+#include "logging.h"
+
+#include <stdexcept>
+
+// The argument must be an expression convertible to bool.
+// Does nothing if the expression evalutes to true. Otherwise
+// it's equivalent to LOG(FATAL).
+#define CHECK(cond...) \
+  static_cast<void>(0), (!!(cond)) ? static_cast<void>(0) : LOG(FATAL) << #cond << ": "
+
+#define VERIFY(cond...)                                               \
+  static_cast<void>(0), ::gitstatus::internal_check::Thrower(!(cond)) \
+                            ? static_cast<void>(0)                    \
+                            : LOG(ERROR) << #cond << ": "
+
+namespace gitstatus {
+
+struct Exception : std::exception {
+  const char* what() const noexcept override { return "Exception"; }
+};
+
+namespace internal_check {
+
+class Thrower {
+ public:
+  Thrower(bool should_throw) : throw_(should_throw) {}
+  Thrower(Thrower&&) = delete;
+  explicit operator bool() const { return !throw_; }
+  ~Thrower() noexcept(false) {
+    if (throw_) throw Exception();
+  }
+
+ private:
+  bool throw_;
+};
+
+}  // namespace internal_check
+
+}  // namespace gitstatus
+
+#endif  // ROMKATV_GITSTATUS_CHECK_H_