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Diffstat (limited to 'src/third_party/boost-1.60.0/boost/multiprecision/cpp_int/checked.hpp')
-rw-r--r-- | src/third_party/boost-1.60.0/boost/multiprecision/cpp_int/checked.hpp | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/src/third_party/boost-1.60.0/boost/multiprecision/cpp_int/checked.hpp b/src/third_party/boost-1.60.0/boost/multiprecision/cpp_int/checked.hpp new file mode 100644 index 00000000000..cafe50ea496 --- /dev/null +++ b/src/third_party/boost-1.60.0/boost/multiprecision/cpp_int/checked.hpp @@ -0,0 +1,149 @@ + +// Copyright 2012 John Maddock. 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_ + +#ifndef BOOST_MP_CPP_INT_CHECKED_HPP +#define BOOST_MP_CPP_INT_CHECKED_HPP + +namespace boost{ namespace multiprecision{ namespace backends{ namespace detail{ + +// +// Simple routines for performing checked arithmetic with a builtin arithmetic type. +// Note that this is not a complete header, it must be included as part of boost/multiprecision/cpp_int.hpp. +// + +inline void raise_overflow(std::string op) +{ + BOOST_THROW_EXCEPTION(std::overflow_error("overflow in " + op)); +} +inline void raise_add_overflow() +{ + raise_overflow("addition"); +} +inline void raise_subtract_overflow() +{ + BOOST_THROW_EXCEPTION(std::range_error("Subtraction resulted in a negative value, but the type is unsigned")); +} +inline void raise_mul_overflow() +{ + raise_overflow("multiplication"); +} +inline void raise_div_overflow() +{ + raise_overflow("division"); +} + +template <class A> +inline A checked_add_imp(A a, A b, const mpl::true_&) +{ + if(a > 0) + { + if((b > 0) && ((integer_traits<A>::const_max - b) < a)) + raise_add_overflow(); + } + else + { + if((b < 0) && ((integer_traits<A>::const_min - b) > a)) + raise_add_overflow(); + } + return a + b; +} +template <class A> +inline A checked_add_imp(A a, A b, const mpl::false_&) +{ + if((integer_traits<A>::const_max - b) < a) + raise_add_overflow(); + return a + b; +} +template <class A> +inline A checked_add(A a, A b, const mpl::int_<checked>&) +{ + return checked_add_imp(a, b, boost::is_signed<A>()); +} +template <class A> +inline A checked_add(A a, A b, const mpl::int_<unchecked>&) +{ + return a + b; +} + +template <class A> +inline A checked_subtract_imp(A a, A b, const mpl::true_&) +{ + if(a > 0) + { + if((b < 0) && ((integer_traits<A>::const_max + b) < a)) + raise_subtract_overflow(); + } + else + { + if((b > 0) && ((integer_traits<A>::const_min + b) > a)) + raise_subtract_overflow(); + } + return a - b; +} +template <class A> +inline A checked_subtract_imp(A a, A b, const mpl::false_&) +{ + if(a < b) + raise_subtract_overflow(); + return a - b; +} +template <class A> +inline A checked_subtract(A a, A b, const mpl::int_<checked>&) +{ + return checked_subtract_imp(a, b, boost::is_signed<A>()); +} +template <class A> +inline A checked_subtract(A a, A b, const mpl::int_<unchecked>&) +{ + return a - b; +} + +template <class A> +inline A checked_multiply(A a, A b, const mpl::int_<checked>&) +{ + BOOST_MP_USING_ABS + if(a && (integer_traits<A>::const_max / abs(a) < abs(b))) + raise_mul_overflow(); + return a * b; +} +template <class A> +inline A checked_multiply(A a, A b, const mpl::int_<unchecked>&) +{ + return a * b; +} + +template <class A> +inline A checked_divide(A a, A b, const mpl::int_<checked>&) +{ + if(b == 0) + raise_div_overflow(); + return a / b; +} +template <class A> +inline A checked_divide(A a, A b, const mpl::int_<unchecked>&) +{ + return a / b; +} + +template <class A> +inline A checked_left_shift(A a, boost::ulong_long_type shift, const mpl::int_<checked>&) +{ + if(a && shift) + { + if((shift > sizeof(A) * CHAR_BIT) || (a >> (sizeof(A) * CHAR_BIT - shift))) + BOOST_THROW_EXCEPTION(std::overflow_error("Shift out of range")); + } + return a << shift; +} +template <class A> +inline A checked_left_shift(A a, boost::ulong_long_type shift, const mpl::int_<unchecked>&) +{ + return (shift >= sizeof(A) * CHAR_BIT) ? 0 : a << shift; +} + +}}}} // namespaces + +#endif + |