I'm trying to integrate some C++ code into Fortran. I have a doubt with equivalences between types,
is Fortran integer*1 equivalent to C++ bool?¿ if not, what is the correct C++ equivalent type?¿
Thank you so much in advance!
2 Answers
quoting from this link:
The INTEGER(1) type should be used for large arrays when memory is at a premium for variables which will have only positive, negative, and zero whole number values within the range of -129 to 127..
So, I'd say its C/C++ equivalent would be a signed char. The equivalent of bool is Fortran's logical type.
EDIT: M.S.B.'s answer is way better than mine; you're way better off doing what (s)he suggested.
2 Comments
Hristo Iliev
I would say the equivalent is
int8_t since there might exist systems with multibyte char-s.
M. S. B.
Fortran logical is frequently 4 bytes but can be one -- risky to match to a type from another language.
The best thing to do is to use the Fortran ISO_C_Binding which provides types that match C types. That approach is compiler and platform independent. I'm less sure about C++ types but if you are sure of their C equivalent you should be good. The ISO_C_Binding provides the Fortran type C_BOOL to match the C type _Bool. The binding provides a long list of equivalent types. One place that the list appears is in the chapter "Intrinsic Modules" of the gfortran manual. Also see the "Mixed Language Programming" chapter. While I have cited the gfortran manual, as part of the Fortran 2003 language standard these features aren't particular to that compiler.
P.S. A comment suggests the use of int8_t. The matching type, on the Fortran side with the ISO C Binding, is C_INT8_T.
