Search results
- Dictionaryshould/ʃʊd/
modal
- 1. used to indicate obligation, duty, or correctness, typically when criticizing someone's actions: "he should have been careful"
- 2. used to indicate what is probable: "£348 m should be enough to buy him out"
Powered by Oxford Dictionaries
Oct 28, 2009 · #define is a compiler pre processor directive and should be used as such, for conditional compilation etc.. E.g. where low level code needs to define some possible alternative data structures for portability to specif hardware. It can produce inconsistent results depending on the order your modules are compiled and linked.
No, not when you consider other .c files including the same header. If the definition of the structure is not visible to the compiler, the details of that definition cannot be used. A declaration without a definition (e.g. just struct s;) causes the compiler to fail if anything tries to look inside struct s, while still allowing it to e.g ...
3. #ifndef checks whether the given token has been #defined earlier in the file or in an included file; if not, it includes the code between it and the closing #else or, if no #else is present, #endif statement. #ifndef is often used to make header files idempotent by defining a token once the file has been included and checking that the token ...
Mar 28, 2018 · Most compilers will allow you to define a macro from the command line (e.g. g++ -DDEBUG something.cpp), but you can also just put a define in your code like so: #define DEBUG Some resources: Wikipedia article; C++ specific site; Documentation on GCC's preprocessor; Microsoft reference; C specific site (I don't think it's different from the C++ ...
Otherwise by using the same argument, you should put parenthesis around everything: int x = y + z; (not a macro) should then with the same flawed logic always be written as int x = (y + z);, in case a stressed non-programmer will maintain the code in the future, to remind them of the dangers of operator precedence.
Nov 4, 2009 · It depends on what you need the value for. You (and everyone else so far) omitted the third alternative: static const int var = 5; #define var 5. enum { var = 5 }; Ignoring issues about the choice of name, then: If you need to pass a pointer around, you must use (1). Since (2) is apparently an option, you don't need to pass pointers around.
A unit’s client needs to access only the header file in order to use the unit. (4) The unit header file shall contain #include statements for all other headers required by the unit header. This lets clients use a unit by including a single header file. (5) The unit body file shall contain an #include statement for the unit header, before all ...
Nov 27, 2015 · The #define directive has two common uses. The first one, is control how the compiler will act. To do this, we also need #undef, #ifdef and #ifndef. (and #endif too...) You can make "compiler logic" this way. A common use is to activate or not a debug portion of the code, like that: #ifdef DEBUG. //debug code here.
Oct 17, 2022 · The clean, reliable way to declare and define global variables is to use a header file to contain an extern declaration of the variable. The header is included by the one source file that defines the variable and by all the source files that reference the variable. For each program, one source file (and only one source file) defines the variable.
Jan 24, 2016 · If not, it will define FILE_H and continue processing the code between it and the #endif directive. The next time that file's contents are seen by the preprocessor, the check against FILE_H will be false, so it will immediately scan down to the #endif and continue after it. This prevents redefinition errors.
