[boost] [exception] uncaught_exception_count, scope(failure), scope(success)

Subject: [boost] [exception] uncaught_exception_count, scope(failure), scope(success)
From: Evgeny Panasyuk (evgeny.panasyuk_at_[hidden])
Date: 2013-02-05 14:11:44

Hello All,

There is implementation of uncaught_exception_count - 
https://github.com/panaseleus/stack_unwinding/blob/master/boost/exception/uncaught_exception_count.hpp 
.

uncaught_exception_count is a function similar to 
std::uncaught_exception from standard library, but instead of boolean 
result it returns unsigned int showing current count of uncaught exceptions.

uncaught_exception_count allow us to implement scope(failure) and 
scope(success) features from D language in C++. ( previous discussion is 
at 
http://boost.2283326.n4.nabble.com/scope-exit-D-style-scope-failure-and-scope-success-in-C-td4636441.html 
)

Implementation of uncaught_exception_count is tested on {Clang 3.2, GCC 
3.4.6, GCC 4.1.2, GCC 4.4.6, GCC 4.4.7, MSVC2005SP1, MSVC2008SP1, 
MSVC2010SP1, MSVC2012} x {x32, x64}.

There are also live stress tests - detection of 500 simultaneous 
uncaught exceptions:
GCC 4.6.3: http://liveworkspace.org/code/2qmSso%240
GCC 4.7.2: http://liveworkspace.org/code/dY0VD%240
Clang 3.2: http://liveworkspace.org/code/49MaPk%240

I think that uncaught_exception_count (and 
uncaught_exception_count_latch primitive) can be added into 
Boost.Exception library, at least into "detail" section.

After that scope(failure) and scope(success) features can be implemented 
in Boost.ScopeExit library.
Note, approximately 14 of 16 Boost.ScopeExit examples in manual are in 
fact emulations of scope(failure)/scope(success). So, looks like in 
first place Boost.ScopeExit was introduced to simplify emulation of 
scope(failure) and scope(success) features.

What do you think?

Thank you.

Best Regards,
Evgeny Panasyuk