Remove non-copyable idioms

[lyx.git] / src / support / ExceptionMessage.h

diff --git a/src/support/ExceptionMessage.h b/src/support/ExceptionMessage.h
index dc597c6547cf6d97ac69fc8e8d9bfbeff27b123a..fea2efa9fdc452eafba1862bfc20a1c868b23d8b 100644 (file)
--- a/src/support/ExceptionMessage.h
+++ b/src/support/ExceptionMessage.h
@@ -22,9 +22,26 @@
 namespace lyx {
 namespace support {
 
+/// LyX support three types of custom exceptions. In order of
+/// increasing seriousness, these are:
+///
+/// WarningException
+///   Intended for unexpected situations that we do not expect
+///   to compromise further operation. It has the effect of 
+///   aborting whatever operation in in process.
+///
+/// BufferException
+///   Intended for situations that indicate some problem with a
+///   Buffer or its related data structures. The Buffer will be
+///   closed, in emergency style.
+///
+/// ErrorException
+///   Intended for situations that indicate a global problem 
+///   with the program. It will lead to an emergency shutdown.
 
 enum ExceptionType {
        ErrorException,
+       BufferException,
        WarningException
 };
 
@@ -33,14 +50,17 @@ class ExceptionMessage: public std::exception {
 public:
        ExceptionMessage(ExceptionType type, docstring const & title,
                docstring const & details)
-               : exception((to_utf8(title) + "\n" + to_utf8(details)).c_str()),
-       type_(type), title_(title), details_(details) {}
+       : type_(type), title_(title), details_(details),
+         message_(to_utf8(title_ + docstring::value_type('\n') + details_)) {}
 
-       virtual ~ExceptionMessage() {}
+       virtual const char * what() const throw() { return message_.c_str(); }
+       virtual ~ExceptionMessage() throw() {}
 
        ExceptionType type_;
        docstring title_;
        docstring details_;
+       // Needed because we may not return a temporary in what().
+       std::string message_;
 };
 
 } // namespace support