1 /*
2     pybind11/operator.h: Metatemplates for operator overloading
3 
4     Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
5 
6     All rights reserved. Use of this source code is governed by a
7     BSD-style license that can be found in the LICENSE file.
8 */
9 
10 #pragma once
11 
12 #include "pybind11.h"
13 
14 #if defined(__clang__) && !defined(__INTEL_COMPILER)
15 #  pragma clang diagnostic ignored "-Wunsequenced" // multiple unsequenced modifications to 'self' (when using def(py::self OP Type()))
16 #elif defined(_MSC_VER)
17 #  pragma warning(push)
18 #  pragma warning(disable: 4127) // warning C4127: Conditional expression is constant
19 #endif
20 
21 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
22 PYBIND11_NAMESPACE_BEGIN(detail)
23 
24 /// Enumeration with all supported operator types
25 enum op_id : int {
26     op_add, op_sub, op_mul, op_div, op_mod, op_divmod, op_pow, op_lshift,
27     op_rshift, op_and, op_xor, op_or, op_neg, op_pos, op_abs, op_invert,
28     op_int, op_long, op_float, op_str, op_cmp, op_gt, op_ge, op_lt, op_le,
29     op_eq, op_ne, op_iadd, op_isub, op_imul, op_idiv, op_imod, op_ilshift,
30     op_irshift, op_iand, op_ixor, op_ior, op_complex, op_bool, op_nonzero,
31     op_repr, op_truediv, op_itruediv, op_hash
32 };
33 
34 enum op_type : int {
35     op_l, /* base type on left */
36     op_r, /* base type on right */
37     op_u  /* unary operator */
38 };
39 
40 struct self_t { };
41 static const self_t self = self_t();
42 
43 /// Type for an unused type slot
44 struct undefined_t { };
45 
46 /// Don't warn about an unused variable
__self()47 inline self_t __self() { return self; }
48 
49 /// base template of operator implementations
50 template <op_id, op_type, typename B, typename L, typename R> struct op_impl { };
51 
52 /// Operator implementation generator
53 template <op_id id, op_type ot, typename L, typename R> struct op_ {
executeop_54     template <typename Class, typename... Extra> void execute(Class &cl, const Extra&... extra) const {
55         using Base = typename Class::type;
56         using L_type = conditional_t<std::is_same<L, self_t>::value, Base, L>;
57         using R_type = conditional_t<std::is_same<R, self_t>::value, Base, R>;
58         using op = op_impl<id, ot, Base, L_type, R_type>;
59         cl.def(op::name(), &op::execute, is_operator(), extra...);
60         #if PY_MAJOR_VERSION < 3
61         if (id == op_truediv || id == op_itruediv)
62             cl.def(id == op_itruediv ? "__idiv__" : ot == op_l ? "__div__" : "__rdiv__",
63                     &op::execute, is_operator(), extra...);
64         #endif
65     }
execute_castop_66     template <typename Class, typename... Extra> void execute_cast(Class &cl, const Extra&... extra) const {
67         using Base = typename Class::type;
68         using L_type = conditional_t<std::is_same<L, self_t>::value, Base, L>;
69         using R_type = conditional_t<std::is_same<R, self_t>::value, Base, R>;
70         using op = op_impl<id, ot, Base, L_type, R_type>;
71         cl.def(op::name(), &op::execute_cast, is_operator(), extra...);
72         #if PY_MAJOR_VERSION < 3
73         if (id == op_truediv || id == op_itruediv)
74             cl.def(id == op_itruediv ? "__idiv__" : ot == op_l ? "__div__" : "__rdiv__",
75                     &op::execute, is_operator(), extra...);
76         #endif
77     }
78 };
79 
80 #define PYBIND11_BINARY_OPERATOR(id, rid, op, expr)                                    \
81 template <typename B, typename L, typename R> struct op_impl<op_##id, op_l, B, L, R> { \
82     static char const* name() { return "__" #id "__"; }                                \
83     static auto execute(const L &l, const R &r) -> decltype(expr) { return (expr); }   \
84     static B execute_cast(const L &l, const R &r) { return B(expr); }                  \
85 };                                                                                     \
86 template <typename B, typename L, typename R> struct op_impl<op_##id, op_r, B, L, R> { \
87     static char const* name() { return "__" #rid "__"; }                               \
88     static auto execute(const R &r, const L &l) -> decltype(expr) { return (expr); }   \
89     static B execute_cast(const R &r, const L &l) { return B(expr); }                  \
90 };                                                                                     \
91 inline op_<op_##id, op_l, self_t, self_t> op(const self_t &, const self_t &) {         \
92     return op_<op_##id, op_l, self_t, self_t>();                                       \
93 }                                                                                      \
94 template <typename T> op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {    \
95     return op_<op_##id, op_l, self_t, T>();                                            \
96 }                                                                                      \
97 template <typename T> op_<op_##id, op_r, T, self_t> op(const T &, const self_t &) {    \
98     return op_<op_##id, op_r, T, self_t>();                                            \
99 }
100 
101 #define PYBIND11_INPLACE_OPERATOR(id, op, expr)                                        \
102 template <typename B, typename L, typename R> struct op_impl<op_##id, op_l, B, L, R> { \
103     static char const* name() { return "__" #id "__"; }                                \
104     static auto execute(L &l, const R &r) -> decltype(expr) { return expr; }           \
105     static B execute_cast(L &l, const R &r) { return B(expr); }                        \
106 };                                                                                     \
107 template <typename T> op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {    \
108     return op_<op_##id, op_l, self_t, T>();                                            \
109 }
110 
111 #define PYBIND11_UNARY_OPERATOR(id, op, expr)                                          \
112 template <typename B, typename L> struct op_impl<op_##id, op_u, B, L, undefined_t> {   \
113     static char const* name() { return "__" #id "__"; }                                \
114     static auto execute(const L &l) -> decltype(expr) { return expr; }                 \
115     static B execute_cast(const L &l) { return B(expr); }                              \
116 };                                                                                     \
117 inline op_<op_##id, op_u, self_t, undefined_t> op(const self_t &) {                    \
118     return op_<op_##id, op_u, self_t, undefined_t>();                                  \
119 }
120 
121 PYBIND11_BINARY_OPERATOR(sub,       rsub,         operator-,    l - r)
122 PYBIND11_BINARY_OPERATOR(add,       radd,         operator+,    l + r)
123 PYBIND11_BINARY_OPERATOR(mul,       rmul,         operator*,    l * r)
124 PYBIND11_BINARY_OPERATOR(truediv,   rtruediv,     operator/,    l / r)
125 PYBIND11_BINARY_OPERATOR(mod,       rmod,         operator%,    l % r)
126 PYBIND11_BINARY_OPERATOR(lshift,    rlshift,      operator<<,   l << r)
127 PYBIND11_BINARY_OPERATOR(rshift,    rrshift,      operator>>,   l >> r)
128 PYBIND11_BINARY_OPERATOR(and,       rand,         operator&,    l & r)
129 PYBIND11_BINARY_OPERATOR(xor,       rxor,         operator^,    l ^ r)
130 PYBIND11_BINARY_OPERATOR(eq,        eq,           operator==,   l == r)
131 PYBIND11_BINARY_OPERATOR(ne,        ne,           operator!=,   l != r)
132 PYBIND11_BINARY_OPERATOR(or,        ror,          operator|,    l | r)
133 PYBIND11_BINARY_OPERATOR(gt,        lt,           operator>,    l > r)
134 PYBIND11_BINARY_OPERATOR(ge,        le,           operator>=,   l >= r)
135 PYBIND11_BINARY_OPERATOR(lt,        gt,           operator<,    l < r)
136 PYBIND11_BINARY_OPERATOR(le,        ge,           operator<=,   l <= r)
137 //PYBIND11_BINARY_OPERATOR(pow,       rpow,         pow,          std::pow(l,  r))
138 PYBIND11_INPLACE_OPERATOR(iadd,     operator+=,   l += r)
139 PYBIND11_INPLACE_OPERATOR(isub,     operator-=,   l -= r)
140 PYBIND11_INPLACE_OPERATOR(imul,     operator*=,   l *= r)
141 PYBIND11_INPLACE_OPERATOR(itruediv, operator/=,   l /= r)
142 PYBIND11_INPLACE_OPERATOR(imod,     operator%=,   l %= r)
143 PYBIND11_INPLACE_OPERATOR(ilshift,  operator<<=,  l <<= r)
144 PYBIND11_INPLACE_OPERATOR(irshift,  operator>>=,  l >>= r)
145 PYBIND11_INPLACE_OPERATOR(iand,     operator&=,   l &= r)
146 PYBIND11_INPLACE_OPERATOR(ixor,     operator^=,   l ^= r)
147 PYBIND11_INPLACE_OPERATOR(ior,      operator|=,   l |= r)
148 PYBIND11_UNARY_OPERATOR(neg,        operator-,    -l)
149 PYBIND11_UNARY_OPERATOR(pos,        operator+,    +l)
150 // WARNING: This usage of `abs` should only be done for existing STL overloads.
151 // Adding overloads directly in to the `std::` namespace is advised against:
152 // https://en.cppreference.com/w/cpp/language/extending_std
153 PYBIND11_UNARY_OPERATOR(abs,        abs,          std::abs(l))
154 PYBIND11_UNARY_OPERATOR(hash,       hash,         std::hash<L>()(l))
155 PYBIND11_UNARY_OPERATOR(invert,     operator~,    (~l))
156 PYBIND11_UNARY_OPERATOR(bool,       operator!,    !!l)
157 PYBIND11_UNARY_OPERATOR(int,        int_,         (int) l)
158 PYBIND11_UNARY_OPERATOR(float,      float_,       (double) l)
159 
160 #undef PYBIND11_BINARY_OPERATOR
161 #undef PYBIND11_INPLACE_OPERATOR
162 #undef PYBIND11_UNARY_OPERATOR
163 PYBIND11_NAMESPACE_END(detail)
164 
165 using detail::self;
166 // Add named operators so that they are accessible via `py::`.
167 using detail::hash;
168 
169 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
170 
171 #if defined(_MSC_VER)
172 #  pragma warning(pop)
173 #endif
174