Files
safe_numerics/include/exception.hpp
2017-05-25 11:01:24 -07:00

136 lines
4.0 KiB
C++

#ifndef BOOST_NUMERIC_EXCEPTION
#define BOOST_NUMERIC_EXCEPTION
// MS compatible compilers support #pragma once
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
// Copyright (c) 2012 Robert Ramey
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// contains error indicators for results of doing checked
// arithmetic on native C++ types
#include <stdexcept>
#include <algorithm>
#include "exception_policies.hpp"
#include "concept/exception_policy.hpp"
namespace boost {
namespace numeric {
// in spite of the similarity, this list is distinct from the exceptions
// listed in documentation for std::exception.
enum class exception_type {
no_exception,
positive_overflow_error,
negative_overflow_error,
underflow_error,
range_error,
domain_error,
implementation_defined_behavior,
undefined_behavior,
uninitialized
};
enum class exception_group {
no_exception,
uninitialized_value,
arithmetic_error,
implementation_defined_behavior,
undefined_behavior
};
// translate exception type to exception handler type
constexpr exception_group
group(const exception_type & et){
// we can't use standard algorithms since we want this to be constexpr
// this brute force solution is simple and pretty fast anyway
switch(et){
case exception_type::negative_overflow_error:
case exception_type::underflow_error:
case exception_type::range_error:
case exception_type::domain_error:
case exception_type::positive_overflow_error:
return exception_group::arithmetic_error;
case exception_type::undefined_behavior:
return exception_group::undefined_behavior;
case exception_type::implementation_defined_behavior:
return exception_group::implementation_defined_behavior;
case exception_type::uninitialized:
return exception_group::uninitialized_value;
case exception_type::no_exception:
return exception_group::no_exception;
}
}
template<class EP>
constexpr exception_handler
handler(const exception_group & eg){
// we can't use standard algorithms since we want this to be constexpr
// this brute force solution is simple and pretty fast anyway
switch(eg){
case exception_group::no_exception:
return exception_handler::ignore_exception;
case exception_group::uninitialized_value:
return EP::on_uninitialized_value();
case exception_group::arithmetic_error:
return EP::on_arithmetic_error();
case exception_group::implementation_defined_behavior:
return EP::on_implementation_defined_behavior();
case exception_group::undefined_behavior:
return EP::on_undefined_behavior();
default:
assert(false);
}
}
constexpr void
throw_exception(const exception_type & e, char const * const & msg){
switch(e){
case exception_type::positive_overflow_error:
case exception_type::negative_overflow_error:
throw std::overflow_error(msg);
case exception_type::underflow_error:
throw std::underflow_error(msg);
case exception_type::range_error:
throw std::range_error(msg);
case exception_type::domain_error:
throw std::domain_error(msg);
case exception_type::implementation_defined_behavior:
case exception_type::undefined_behavior:
case exception_type::uninitialized:
case exception_type::no_exception:
default:
assert(false);
}
};
template<class EP>
constexpr void
dispatch(const exception_type & e, char const * const & msg){
const exception_group eg = group(e);
const exception_handler eh = handler<EP>(eg);
switch(eh){
case exception_handler::ignore_exception:
return;
case exception_handler::throw_exception:
throw_exception(e, msg);
case exception_handler::trap_exception:
assert(false);
default:
assert(false);
}
}
} // numeric
} // boost
#endif // BOOST_NUMERIC_CHECKED_RESULT