[Boost-users] [Boost.Test] BOOST_CHECK_THROW behaviour

Subject: [Boost-users] [Boost.Test] BOOST_CHECK_THROW behaviour
From: Ghyslain Leclerc (ghleclerc_at_[hidden])
Date: 2014-06-19 09:03:38

Hello,

Sorry for the long post!

I have a simple class, which I am posting a fraction of here for discussion sake:

------------------------------------------------------
class AsciiTableRow
{
public:
   void setCol( std::size_t colIdx, std::string const& newContent );
   void setCol( std::size_t colIdx, const char* newContent );

private:
   void checkIdxBound_( std::size_t colIdx, std::string const& msg );

   std::vector< std::string > data_;
   bool maxColWidthIsValid_;
}

inline  void AsciiTableRow::setCol( std::size_t colIdx, std::string const& newVal )
{
   checkIdxBound_( colIdx, "setCol" );
   maxColWidthIsValid_ = false;
   data_[colIdx] = newVal;
}

inline  void AsciiTableRow::setCol( std::size_t colIdx, const char* newContent )
{
   setCol( colIdx, std::string( newContent ) );
}

inline void AsciiTableRow::checkIdxBound_( std::size_t colIdx, std::string const& msg )
{
   if( colIdx > data_.size() )
   {
      throw std::out_of_range( "AsciiTableRow::" + msg + " : colIdx out of range" );
   }
}

------------------------------------------------------

The code above should be sufficient for the discussion and I don’t think any other code is relevant.  Should you need to see my constructor and destructor, nothing is virtual so I just copy every value and set some defaults.  Nothing fancy, but I will gladly post the code if need be.

What I do then is try and devise a test to see if the exception is indeed thrown and if it is the correct one. Â Here is the code I use:

AsciiTableRow testRow; Â // empty, so any index will throw
BOOST_CHECK_THROW( testRow.setCol( 30, 12 ), std::out_of_range );
BOOST_CHECK_THROW( testRow.setCol( 30, 12l ), std::out_of_range );

This works fine. Â Then, I had the idea to check what the behaviour would be if the wrong exception is thrown. Â I simply changed the first call like this :

BOOST_CHECK_THROW( testRow.setCol( 30, 12 ), std::runtime_error );
BOOST_CHECK_THROW( testRow.setCol( 30, 12l ), std::out_of_range );

I was under the impression (and I might be wrong here, sorry  :-(   ) that the Boost.Test library would (the numbers are not to mean that order, simply there for enumeration):
1- output a message saying the test has failed, that an exception was indeed thrown, but it was not a runtime_error
2- continue the rest of the test (single test currently)
3- terminate

but I actually never get the message of step 1, the execution of the rest of the test seems never occur (the second BOOST_CHECK_THROW) and the program terminate because of my exception and not very gracefully.

I guess my questions to the other users here are:
  - Was my understanding of what BOOST_CHECK_THROW does flawed ?
  - Is the behaviour normal ?
  - Is there an obvious problem I am missing with the design of my simple class ?

In case it is useful, I am on OSX 10.9. Â I have compiled boost myself (sources of version 1.55 downloaded from the Boost site). Â I compile my work with C++11 enabled. Â I am using GCC 4.7 installed via Macports.

Anyhow, any insight will be appreciated.

As everyone is busy, thanks in advance to anybody for any time spent on this.

Ghyslain