python-dev python-dev contains the header files you need to build Python extensions. lxml lxml is a Python C-API extension that is compiled when you do pip install lxml. The lxml sources have at least something like #include <Python.h> in the code. The compiler looks for the header file Python.h during compilation, hence those header files … Read more
conio.h is a C header file used with old MS-DOS compilers to create text user interfaces. Compilers that target other operating systems, such as Linux-based, 32-bit Windows and OS/2, provide equivalent functionality through other header files and libraries. The #include <curses.h> will give you almost all of the functionality provided by conio.h. “ncurses” needs to … Read more
If a class member is always initialized with the same initial value, then you should make the initializer inline, so as to avoid duplication. If the initial value depends on the constructor, then put it in the constructor initializer list. (And never use assignment in the way you did.) Example: class Foo { bool done … Read more
From a code readability standpoint, it is probably better in my opinion to use the #2 method for this reason: You can be using multiple namespaces at a time, and any object or function written below that line can belong to any of those namespaces (barring naming conflicts). Wrapping the whole file in a namespace … Read more
Ok, not a C/C++ expert by any means, but I thought the point of a header file was to declare the functions, then the C/CPP file was to define the implementation. The true purpose of a header file is to share code amongst multiple source files. It is commonly used to separate declarations from implementations … Read more
If you are using a GNU compiler, the compiler can assemble a list of dependencies for you. Makefile fragment: depend: .depend .depend: $(SRCS) rm -f “$@” $(CC) $(CFLAGS) -MM $^ -MF “$@” include .depend or depend: .depend .depend: $(SRCS) rm -f “$@” $(CC) $(CFLAGS) -MM $^ > “$@” include .depend where SRCS is a variable … Read more
Header files (.h) are designed to provide the information that will be needed in multiple files. Things like class declarations, function prototypes, and enumerations typically go in header files. In a word, “definitions”. Code files (.cpp) are designed to provide the implementation information that only needs to be known in one file. In general, function … Read more
You should definitely NOT use using namespace in headers for precisely the reason you say, that it can unexpectedly change the meaning of code in any other files that include that header. There’s no way to undo a using namespace which is another reason it’s so dangerous. I typically just use grep or the like … Read more
#pragma once is not standard. It is a widespread (but not universal) extension, which can be used if your portability concerns are limited, and you can be sure that all of your include files are always on a local disk. It was considered for standardization, but rejected because it cannot be implemented reliably. (The problems … Read more