All Questions
Tagged with c-preprocessor constants
78
questions
0
votes
1
answer
144
views
Is a C compile-time constant applied the same as a preprocessor define variable after compile time? [duplicate]
What I'm asking is does a C const variable defined in such a way that its value is known at compile time:
const int num = 3;
int main(){
int arr[num];
}
act in the same way as a preprocessor ...
- 167
1
vote
1
answer
61
views
Conditional inclusion: numeric value for the character constants: within #if/#elif vs. without #if/#elif: why matching is implementation-defined?
Case A: C11, 6.6 Constant expressions, Semantics, 5:
If a floating expression is evaluated in the translation environment, the arithmetic range and precision shall be at least as great as if the ...
- 6,179
0
votes
0
answers
48
views
how to convert a #defined item to a string in c++? [duplicate]
Suppose I have defined an item
#define CLASSNAME MyClass
and I then want the preprocessor to generate a string constant "MyClass"
e.g
std::string str("MyClass")
I cannot of ...
- 291
-2
votes
1
answer
356
views
Trying to replace #define with const does work
So I originally wrote my program using #define since I know it happens as a preprocessor, but my teacher commented that I should use const. I tried replacing #define in my code but it just broke it ...
0
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0
answers
35
views
what's the use case of define preprocessor directive? [duplicate]
I am writing a c program consisting of 5 modules, each with an associated header file where functions prototypes are written.
Only, I have a c file/header pair that I only use for defining constant ...
- 175
0
votes
2
answers
2k
views
Can I #define a constant solutionwide within c# code without project settings?
I know this was aksed and answered a a couple of times e.g.
Solution-wide #define, Is There anyway to #define Constant on a Solution Basis? and How to define a constant globally in C# (like DEBUG).
...
- 89.6k
-1
votes
1
answer
3k
views
Best way to declare a constant string in C [duplicate]
I have a string: "The world is a beautiful place to live in.".
I have two source files and a global header file. I can access the string in two easy ways:-
Declaring and defining a constant ...
- 1,061
1
vote
3
answers
4k
views
Evaluate all macros in a C++ header file
I have a requirement to build an automated system to parse a C++ .h file with a lot of #define statements in it and do something with the value that each #define works out to. The .h file has a lot of ...
- 2,056
1
vote
4
answers
164
views
C char of string to array
I have 2 defines, one with a string and one with a number.How can i make a const array from the define with the string and the number. There are also some additional constant which should be in this ...
0
votes
2
answers
67
views
How to assign const static with an incremental macro?
I am trying to assign an unique value to const static unsigned int members, without having to think about assigning the right values myself (preventing human errors). I've created a minimal solution ...
- 672
1
vote
1
answer
105
views
C++ and Swift Don't Like Each Other
I am trying to use a C++ library named MP4v2 in Swift. It is mostly working in that I can can call some functions, use some classes, etc.
I am having trouble with a particular function that returns a ...
- 5,551
0
votes
2
answers
88
views
Is using object-like macros a good way to define global variables?
I've been told by my teacher that the preprocessor command #define is the way to go to declare a global variable. Basically I use the object-like macros
#define x 3
to declare x as a global variable....
- 1,380
6
votes
4
answers
2k
views
How are chained macros resolved in C?
If I want to use preprocessor #define statements for easy definition and calculation of constants and common functions and take advantage of less RAM overhead (as opposed to using const values). ...
- 1,104
1
vote
3
answers
3k
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How to pre-define an array in c?
#include <stdio.h>
#include <math.h>
#define Hey {0.9501, 0.2311, 0.6068, 0.4860, 0.8913, 0.7621, 0.4565, 0.0185, 0.8214, 0.4447, 0.6154, 0.7919, 0.9218, 0.7382, 0.1763, 0.4057, 0.9355, 0....
- 125
4
votes
1
answer
434
views
Why use both anonymous enum and define macros for constants? [duplicate]
Why netinet/in.h defines constants this way?
enum
{
IPPROTO_IP = 0,
#define IPPROTO_IP IPPROTO_IP
IPPROTO_HOPOPTS = 0,
#define IPPROTO_HOPOPTS IPPROTO_HOPOPTS
...
- 17.7k