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python/include/boost/python/operators.hpp
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'Version_1_21_0'.

[SVN r9525]
2001-03-09 14:58:07 +00:00

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// (C) Copyright Ullrich Koethe and David Abrahams 2000-2001. Permission to
// copy, use, modify, sell and distribute this software is granted provided
// this copyright notice appears in all copies. This software is provided "as
// is" without express or implied warranty, and with no claim as to its
// suitability for any purpose.
//
// The authors gratefully acknowlege the support of Dragon Systems, Inc., in
// producing this work.
//
// Revision History:
// 23 Jan 2001 - Another stupid typo fix by Ralf W. Grosse-Kunstleve (David Abrahams)
// 20 Jan 2001 - Added a fix from Ralf W. Grosse-Kunstleve (David Abrahams)
#ifndef OPERATORS_UK112000_H_
#define OPERATORS_UK112000_H_
# include <boost/python/reference.hpp>
# include <boost/python/detail/functions.hpp>
// When STLport is used with native streams, _STL::ostringstream().str() is not
// _STL::string, but std::string. This confuses to_python(), so we'll use
// strstream instead. Also, GCC 2.95.2 doesn't have sstream.
# if defined(__SGI_STL_PORT) ? defined(__SGI_STL_OWN_IOSTREAMS) : (!defined(__GNUC__) || __GNUC__ > 2)
# define BOOST_PYTHON_USE_SSTREAM
# endif
#if defined(BOOST_PYTHON_USE_SSTREAM)
# include <sstream>
# else
# include <strstream>
# endif
namespace boost { namespace python {
tuple standard_coerce(ref l, ref r);
namespace detail {
// helper class for automatic operand type detection
// during operator wrapping.
struct auto_operand {};
}
// Define operator ids that can be or'ed together
// (boost::python::op_add | boost::python::op_sub | boost::python::op_mul).
// This allows to wrap several operators in one line.
enum operator_id
{
op_add = 0x1,
op_sub = 0x2,
op_mul = 0x4,
op_div = 0x8,
op_mod = 0x10,
op_divmod =0x20,
op_pow = 0x40,
op_lshift = 0x80,
op_rshift = 0x100,
op_and = 0x200,
op_xor = 0x400,
op_or = 0x800,
op_neg = 0x1000,
op_pos = 0x2000,
op_abs = 0x4000,
op_invert = 0x8000,
op_int = 0x10000,
op_long = 0x20000,
op_float = 0x40000,
op_str = 0x80000,
op_cmp = 0x100000
};
// Wrap the operators given by "which". Usage:
// foo_class.def(boost::python::operators<(boost::python::op_add | boost::python::op_sub)>());
template <long which, class operand = boost::python::detail::auto_operand>
struct operators {};
// Wrap heterogeneous operators with given left operand type. Usage:
// foo_class.def(boost::python::operators<(boost::python::op_add | boost::python::op_sub)>(),
// boost::python::left_operand<int>());
template <class T>
struct left_operand {};
// Wrap heterogeneous operators with given right operand type. Usage:
// foo_class.def(boost::python::operators<(boost::python::op_add | boost::python::op_sub)>(),
// boost::python::right_operand<int>());
template <class T>
struct right_operand {};
namespace detail
{
template <class Specified>
struct operand_select
{
template <class wrapped_type>
struct wrapped
{
typedef Specified type;
};
};
template <>
struct operand_select<auto_operand>
{
template <class wrapped_type>
struct wrapped
{
typedef const wrapped_type& type;
};
};
template <long> struct define_operator;
// Base class which grants access to extension_class_base::add_method() to its derived classes
struct add_operator_base
{
protected:
static inline void add_method(extension_class_base* target, function* method, const char* name)
{ target->add_method(method, name); }
};
//
// choose_op, choose_unary_op, and choose_rop
//
// These templates use "poor man's partial specialization" to generate the
// appropriate add_method() call (if any) for a given operator and argument set.
//
// Usage:
// choose_op<(which & op_add)>::template args<left_t,right_t>::add(ext_class);
//
// (see extension_class<>::def_operators() for more examples).
//
template <long op_selector>
struct choose_op
{
template <class Left, class Right = Left>
struct args : add_operator_base
{
static inline void add(extension_class_base* target)
{
typedef define_operator<op_selector> def_op;
add_method(target,
new typename def_op::template operator_function<Left, Right>(),
def_op::name());
}
};
};
// specialization for 0 has no effect
template <>
struct choose_op<0>
{
template <class Left, class Right = Left>
struct args
{
static inline void add(extension_class_base*)
{
}
};
};
template <long op_selector>
struct choose_unary_op
{
template <class Operand>
struct args : add_operator_base
{
static inline void add(extension_class_base* target)
{
typedef define_operator<op_selector> def_op;
add_method(target,
new typename def_op::template operator_function<Operand>(),
def_op::name());
}
};
};
// specialization for 0 has no effect
template <>
struct choose_unary_op<0>
{
template <class Operand>
struct args
{
static inline void add(extension_class_base*)
{
}
};
};
template <long op_selector>
struct choose_rop
{
template <class Left, class Right = Left>
struct args : add_operator_base
{
static inline void add(extension_class_base* target)
{
typedef define_operator<op_selector> def_op;
add_method(target,
new typename def_op::template roperator_function<Right, Left>(),
def_op::rname());
}
};
};
// specialization for 0 has no effect
template <>
struct choose_rop<0>
{
template <class Left, class Right = Left>
struct args
{
static inline void add(extension_class_base*)
{
}
};
};
// Fully specialize define_operator for all operators defined in operator_id above.
// Every specialization defines one function object for normal operator calls and one
// for operator calls with operands reversed ("__r*__" function variants).
// Specializations for most operators follow a standard pattern: execute the expression
// that uses the operator in question. This standard pattern is realized by the following
// macros so that the actual specialization can be done by just calling a macro.
#define PY_DEFINE_BINARY_OPERATORS(id, oper) \
template <> \
struct define_operator<op_##id> \
{ \
template <class Left, class Right = Left> \
struct operator_function : function \
{ \
PyObject* do_call(PyObject* arguments, PyObject* /* keywords */) const \
{ \
tuple args(ref(arguments, ref::increment_count)); \
\
return BOOST_PYTHON_CONVERSION::to_python( \
BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Left>()) oper \
BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Right>())); \
} \
\
const char* description() const \
{ return "__" #id "__"; } \
}; \
\
template <class Right, class Left> \
struct roperator_function : function \
{ \
PyObject* do_call(PyObject* arguments, PyObject* /* keywords */) const \
{ \
tuple args(ref(arguments, ref::increment_count)); \
\
return BOOST_PYTHON_CONVERSION::to_python( \
BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Left>()) oper \
BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Right>())); \
} \
\
const char* description() const \
{ return "__r" #id "__"; } \
\
}; \
\
static const char * name() { return "__" #id "__"; } \
static const char * rname() { return "__r" #id "__"; } \
}
#define PY_DEFINE_UNARY_OPERATORS(id, oper) \
template <> \
struct define_operator<op_##id> \
{ \
template <class operand> \
struct operator_function : function \
{ \
PyObject* do_call(PyObject* arguments, PyObject* /* keywords */) const \
{ \
tuple args(ref(arguments, ref::increment_count)); \
\
return BOOST_PYTHON_CONVERSION::to_python( \
oper(BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<operand>()))); \
} \
\
const char* description() const \
{ return "__" #id "__"; } \
}; \
\
static const char * name() { return "__" #id "__"; } \
}
PY_DEFINE_BINARY_OPERATORS(add, +);
PY_DEFINE_BINARY_OPERATORS(sub, -);
PY_DEFINE_BINARY_OPERATORS(mul, *);
PY_DEFINE_BINARY_OPERATORS(div, /);
PY_DEFINE_BINARY_OPERATORS(mod, %);
PY_DEFINE_BINARY_OPERATORS(lshift, <<);
PY_DEFINE_BINARY_OPERATORS(rshift, >>);
PY_DEFINE_BINARY_OPERATORS(and, &);
PY_DEFINE_BINARY_OPERATORS(xor, ^);
PY_DEFINE_BINARY_OPERATORS(or, |);
PY_DEFINE_UNARY_OPERATORS(neg, -);
PY_DEFINE_UNARY_OPERATORS(pos, +);
PY_DEFINE_UNARY_OPERATORS(abs, abs);
PY_DEFINE_UNARY_OPERATORS(invert, ~);
PY_DEFINE_UNARY_OPERATORS(int, long);
PY_DEFINE_UNARY_OPERATORS(long, PyLong_FromLong);
PY_DEFINE_UNARY_OPERATORS(float, double);
#undef PY_DEFINE_BINARY_OPERATORS
#undef PY_DEFINE_UNARY_OPERATORS
// Some operators need special treatment, e.g. because there is no corresponding
// expression in C++. These are specialized manually.
// pow(): Manual specialization needed because an error message is required if this
// function is called with three arguments. The "power modulo" operator is not
// supported by define_operator, but can be wrapped manually (see special.html).
template <>
struct define_operator<op_pow>
{
template <class Left, class Right = Left>
struct operator_function : function
{
PyObject* do_call(PyObject* arguments, PyObject* /* keywords */) const
{
tuple args(ref(arguments, ref::increment_count));
if (args.size() == 3 && args[2]->ob_type != Py_None->ob_type)
{
PyErr_SetString(PyExc_TypeError, "expected 2 arguments, got 3");
throw argument_error();
}
return BOOST_PYTHON_CONVERSION::to_python(
pow(BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Left>()),
BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Right>())));
}
const char* description() const
{ return "__pow__"; }
};
template <class Right, class Left>
struct roperator_function : function
{
PyObject* do_call(PyObject* arguments, PyObject* /* keywords */) const
{
tuple args(ref(arguments, ref::increment_count));
if (args.size() == 3 && args[2]->ob_type != Py_None->ob_type)
{
PyErr_SetString(PyExc_TypeError, "bad operand type(s) for pow()");
throw argument_error();
}
return BOOST_PYTHON_CONVERSION::to_python(
pow(BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Left>()),
BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Right>())));
}
const char* description() const
{ return "__rpow__"; }
};
static const char * name() { return "__pow__"; }
static const char * rname() { return "__rpow__"; }
};
// divmod(): Manual specialization needed because we must actually call two operators and
// return a tuple containing both results
template <>
struct define_operator<op_divmod>
{
template <class Left, class Right = Left>
struct operator_function : function
{
PyObject* do_call(PyObject* arguments, PyObject* /* keywords */) const
{
tuple args(ref(arguments, ref::increment_count));
PyObject * res = PyTuple_New(2);
PyTuple_SET_ITEM(res, 0,
BOOST_PYTHON_CONVERSION::to_python(
BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Left>()) /
BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Right>())));
PyTuple_SET_ITEM(res, 1,
BOOST_PYTHON_CONVERSION::to_python(
BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Left>()) %
BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Right>())));
return res;
}
const char* description() const
{ return "__divmod__"; }
};
template <class Right, class Left>
struct roperator_function : function
{
PyObject* do_call(PyObject* arguments, PyObject* /* keywords */) const
{
tuple args(ref(arguments, ref::increment_count));
PyObject * res = PyTuple_New(2);
PyTuple_SET_ITEM(res, 0,
BOOST_PYTHON_CONVERSION::to_python(
BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Left>()) /
BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Right>())));
PyTuple_SET_ITEM(res, 1,
BOOST_PYTHON_CONVERSION::to_python(
BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Left>()) %
BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Right>())));
return res;
}
const char* description() const
{ return "__rdivmod__"; }
};
static const char * name() { return "__divmod__"; }
static const char * rname() { return "__rdivmod__"; }
};
// cmp(): Manual specialization needed because there is no three-way compare in C++.
// It is implemented by two one-way comparisons with operators reversed in the second.
template <>
struct define_operator<op_cmp>
{
template <class Left, class Right = Left>
struct operator_function : function
{
PyObject* do_call(PyObject* arguments, PyObject* /* keywords */) const
{
tuple args(ref(arguments, ref::increment_count));
return BOOST_PYTHON_CONVERSION::to_python(
(BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Left>()) <
BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Right>())) ?
- 1 :
(BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Right>()) <
BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Left>())) ?
1 :
0) ;
}
const char* description() const
{ return "__cmp__"; }
};
template <class Right, class Left>
struct roperator_function : function
{
PyObject* do_call(PyObject* arguments, PyObject* /* keywords */) const
{
tuple args(ref(arguments, ref::increment_count));
return BOOST_PYTHON_CONVERSION::to_python(
(BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Left>()) <
BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Right>())) ?
- 1 :
(BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<Right>()) <
BOOST_PYTHON_CONVERSION::from_python(args[1].get(), boost::python::type<Left>())) ?
1 :
0) ;
}
const char* description() const
{ return "__rcmp__"; }
};
static const char * name() { return "__cmp__"; }
static const char * rname() { return "__rcmp__"; }
};
# ifndef BOOST_PYTHON_USE_SSTREAM
class unfreezer {
public:
unfreezer(std::ostrstream& s) : m_stream(s) {}
~unfreezer() { m_stream.freeze(false); }
private:
std::ostrstream& m_stream;
};
# endif
// str(): Manual specialization needed because the string conversion does not follow
// the standard pattern relized by the macros.
template <>
struct define_operator<op_str>
{
template <class operand>
struct operator_function : function
{
PyObject* do_call(PyObject* arguments, PyObject*) const
{
tuple args(ref(arguments, ref::increment_count));
// When STLport is used with native streams, _STL::ostringstream().str() is not
// _STL::string, but std::string.
# ifdef BOOST_PYTHON_USE_SSTREAM
std::ostringstream s;
s << BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<operand>());
return BOOST_PYTHON_CONVERSION::to_python(s.str());
# else
std::ostrstream s;
s << BOOST_PYTHON_CONVERSION::from_python(args[0].get(), boost::python::type<operand>()) << char();
auto unfreezer unfreeze(s);
return BOOST_PYTHON_CONVERSION::to_python(const_cast<char const *>(s.str()));
# endif
}
const char* description() const
{ return "__str__"; }
};
static const char * name() { return "__str__"; }
};
} // namespace detail
}} // namespace boost::python
# undef BOOST_PYTHON_USE_SSTREAM
#endif /* OPERATORS_UK112000_H_ */