xref: /petsc/include/petsccxxcomplexfix.h (revision be39004295a98ced168607de69334a8b204d0588)
1 #pragma once
2 
3 /* MANSEC = Sys */
4 
5 /*
6     The pragma below silence all compiler warnings coming from code in this header file.
7     In particular, it silences `-Wfloat-equal` warnings in `operator==()` and `operator!=` below.
8     Other compilers beyond GCC support this pragma.
9 */
10 #if defined(__GNUC__) && (__GNUC__ >= 4) && !defined(__NEC__)
11   #pragma GCC system_header
12 #endif
13 
14 /*
15      Defines additional operator overloading for the C++ complex class that are "missing" in the standard
16      include files. For example, the code fragment
17 
18      std::complex<double> c = 22.0;
19      c = 11 + c;
20 
21      will produce a compile time error such as
22 
23      error: no match for 'operator+' (operand types are 'int' and 'std::complex<double>')
24 
25      The code fragment
26 
27      std::complex<float> c = 22.0;
28      c = 11.0 + c;
29 
30      will produce a compile time error such as
31 
32      error: no match for 'operator+' (operand types are 'double' and 'std::complex<float>')
33 
34      This deficiency means one may need to write cumbersome code while working with the C++ complex classes.
35 
36      This include file defines a few additional operator overload methods for the C++ complex classes to handle
37      these cases naturally within PETSc code.
38 
39      This file is included in petscsystypes.h when feasible. In the small number of cases where these additional methods
40      may conflict with other code one may add '#define PETSC_SKIP_CXX_COMPLEX_FIX 1' before including any PETSc include
41      files to prevent these methods from being provided.
42 */
43 
44 #define PETSC_CXX_COMPLEX_FIX(Type) \
45   static inline PetscComplex operator+(const PetscComplex &lhs, const Type &rhs) \
46   { \
47     return const_cast<PetscComplex &>(lhs) + PetscReal(rhs); \
48   } \
49   static inline PetscComplex operator+(const Type &lhs, const PetscComplex &rhs) \
50   { \
51     return PetscReal(lhs) + const_cast<PetscComplex &>(rhs); \
52   } \
53   static inline PetscComplex operator-(const PetscComplex &lhs, const Type &rhs) \
54   { \
55     return const_cast<PetscComplex &>(lhs) - PetscReal(rhs); \
56   } \
57   static inline PetscComplex operator-(const Type &lhs, const PetscComplex &rhs) \
58   { \
59     return PetscReal(lhs) - const_cast<PetscComplex &>(rhs); \
60   } \
61   static inline PetscComplex operator*(const PetscComplex &lhs, const Type &rhs) \
62   { \
63     return const_cast<PetscComplex &>(lhs) * PetscReal(rhs); \
64   } \
65   static inline PetscComplex operator*(const Type &lhs, const PetscComplex &rhs) \
66   { \
67     return PetscReal(lhs) * const_cast<PetscComplex &>(rhs); \
68   } \
69   static inline PetscComplex operator/(const PetscComplex &lhs, const Type &rhs) \
70   { \
71     return const_cast<PetscComplex &>(lhs) / PetscReal(rhs); \
72   } \
73   static inline PetscComplex operator/(const Type &lhs, const PetscComplex &rhs) \
74   { \
75     return PetscReal(lhs) / const_cast<PetscComplex &>(rhs); \
76   } \
77   static inline bool operator==(const PetscComplex &lhs, const Type &rhs) \
78   { \
79     return const_cast<PetscComplex &>(lhs).imag() == PetscReal(0) && const_cast<PetscComplex &>(lhs).real() == PetscReal(rhs); \
80   } \
81   static inline bool operator==(const Type &lhs, const PetscComplex &rhs) \
82   { \
83     return const_cast<PetscComplex &>(rhs).imag() == PetscReal(0) && const_cast<PetscComplex &>(rhs).real() == PetscReal(lhs); \
84   } \
85   static inline bool operator!=(const PetscComplex &lhs, const Type &rhs) \
86   { \
87     return const_cast<PetscComplex &>(lhs).imag() != PetscReal(0) || const_cast<PetscComplex &>(lhs).real() != PetscReal(rhs); \
88   } \
89   static inline bool operator!=(const Type &lhs, const PetscComplex &rhs) \
90   { \
91     return const_cast<PetscComplex &>(rhs).imag() != PetscReal(0) || const_cast<PetscComplex &>(rhs).real() != PetscReal(lhs); \
92   } \
93 /* PETSC_CXX_COMPLEX_FIX */
94 
95 /*
96     Due to the C++ automatic promotion rules for floating point and integer values only the two cases below
97     need to be handled.
98 */
99 #if defined(PETSC_USE_REAL_SINGLE)
100 PETSC_CXX_COMPLEX_FIX(double)
101 #elif defined(PETSC_USE_REAL_DOUBLE)
102 PETSC_CXX_COMPLEX_FIX(PetscInt)
103 #endif /* PETSC_USE_REAL_* */
104