1 files changed, 85 insertions, 0 deletions
diff --git a/build2/utility b/build2/utility
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+// file      : build2/utility -*- C++ -*-
+// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BUILD2_UTILITY
+#define BUILD2_UTILITY
+
+#include <utility>       // move(), make_pair()
+#include <cassert>       // assert()
+#include <exception>     // uncaught_exception()
+#include <unordered_set>
+
+#include <build2/types>
+
+namespace build2
+{
+  using std::move;
+  using std::make_pair;
+
+  // Empty string and path.
+  //
+  extern const std::string empty_string;
+  extern const path empty_path;
+  extern const dir_path empty_dir_path;
+
+  // Parse version string in the X.Y.Z[-{a|b}N] to a version integer in the
+  // AABBCCDD form as describe in <build2/version>. Throw invalid_argument
+  // if the passed string is not a valid version.
+  //
+  unsigned int
+  to_version (const string&);
+
+  // Call a function if there is an exception.
+  //
+
+  // Means we are in the body of a destructor that is being called
+  // as part of the exception stack unwindining. Used to compensate
+  // for the deficiencies of uncaught_exception() until C++17
+  // uncaught_exceptions() becomes available.
+  //
+  // @@ MT: will have to be TLS.
+  //
+  extern bool exception_unwinding_dtor;
+
+  template <typename F>
+  struct exception_guard;
+
+  template <typename F>
+  inline exception_guard<F>
+  make_exception_guard (F f)
+  {
+    return exception_guard<F> (move (f));
+  }
+
+  template <typename F>
+  struct exception_guard
+  {
+    exception_guard (F f): f_ (move (f)) {}
+    ~exception_guard ()
+    {
+      if (std::uncaught_exception ())
+      {
+        exception_unwinding_dtor = true;
+        f_ ();
+        exception_unwinding_dtor = false;
+      }
+    }
+
+  private:
+    F f_;
+  };
+
+  // Pools (@@ perhaps move into a separate header).
+  //
+  struct string_pool: std::unordered_set<std::string>
+  {
+    const std::string&
+    find (const char* s) {return *emplace (s).first;}
+
+    const std::string&
+    find (const std::string& s) {return *emplace (s).first;}
+  };
+}
+
+#endif // BUILD2_UTILITY