A macro in computer science is a rule or pattern that specifies how a certain input sequence (often a sequence of characters) should be mapped to a replacement output sequence (also often a sequence of characters) according to a defined procedure. Do not use this tag for questions regarding ...
14
votes
3answers
992 views
On-the-fly destructors
Due to my needing to use C libraries inside C++, I kept finding myself wanting to be able to ensure that the free function got called, even if an exception got ...
14
votes
2answers
168 views
Formatted print without the need to specify type matching specifiers using _Generic
This code allows printing in C with a style similar to C++ ostream. By using _Generic() (see ...
13
votes
2answers
1k views
Template vector struct in C11
This one review will be a little bit tricky: I was trying to implement a template Vector struct in C11. Of course, templates don't really exist in C11, so I used a ...
13
votes
0answers
148 views
Suggesting “safe enum” class for ISO C
There are quite some questions and answers about how to make enum really type-safe and I didn't find a solution that ensures both type safety and valid values. So I ...
12
votes
3answers
804 views
Endianness conversion in C
I have written a simple C header for converting the endianness of short integers and long integers. It uses the GCC macro ...
12
votes
3answers
7k views
Generic C++ exception catch handler macro
I have this set of legacy C++ projects with a large number of public functions. At the start, none of those publicly exposed functions had try..catch insulation ...
12
votes
1answer
175 views
Lua bindings for FTGL (FreeType font rendering in OpenGL)
I wrote some Lua bindings for FTGL's C API. This works well enough, but I ended up with lots of macros, one for each Lua function signature. For example, LUD_NUMBER_NUMBER_TO_NUMBER creates a Lua ...
11
votes
3answers
1k views
Validity of macro for printf() call in a corporate environment
I wrote this program:
#include <stdio.h>
#define printS for(i=0;s[i];i++){printf("%c",s[i]);}
int i;
char s[] = "Hello World!\n";
void main()
{
printS;
}
...
11
votes
5answers
2k views
11
votes
1answer
233 views
Macro to build type declaration
These are some macros to help build a traits class (for the parser/printer classes I am building).
Traits.h
...
9
votes
5answers
702 views
Resolving a link - follow-up
Similar piece of code to that I recently posted as:
Resolving a link
I have another piece of code which cannot be as easily extracted out into a method:
...
8
votes
2answers
2k views
Macro that interchanges 2 arguments
Define a macro swap(t, x, y) that interchanges two arguments of type t.(Block structure will help.)
The ideea is that a ...
8
votes
2answers
2k views
A tuple unpacking macro that approximates Python elegance
Motivation
Although I love coding in C++, I sometimes yearn for the syntactic sugar of Python. C++11 has somewhat eased the pain by such beautiful analogies like this:
...
8
votes
0answers
163 views
Autotools detect C++ language standard support
I have been updating my build tools to optionally use autotools (autoconfig/automake/libtool etc.).
As part of this change I have written a couple of M4 macros. This not being something I have done ...
7
votes
6answers
901 views
Length of a C string, capped to some maximum
If I have a oneliner in C such as
size_t maxSizeOf(const char *s)
{
return strlen(s) > M_MAX_SIZE ? M_MAX_SIZE : strlen(s);
}
would it be better to have ...
7
votes
4answers
2k views
'do { statement; } while(0)' against 'statement' when writing C macro? [closed]
Which one of the following is preferrable and why when writing C macro?
Type 1
#define I2C_START() I2C_WAIT_IDLE(); SSP1CON2bits.SEN = 1
Type 2
...
7
votes
1answer
4k views
Variadic macro enum class “reflection” in C++11
I recently had the need of "reflecting" multiple enum class constructs in order to get their elements' names as std::string ...
7
votes
1answer
215 views
Source code level portable C++ Unicode literals
Windows console windows do unfortunately not support stream I/O of international characters. For instance, in Windows 7, you can still do "chcp 65001" (sets the active code page to UTF-8), type "more",...
7
votes
1answer
134 views
Validation macro
I would like a review of a Scala validation library I am writing. For now we can focus on the regular expression component.
The usage is described in RegexExample.scala
There is an outline of the ...
6
votes
3answers
246 views
Macro enabling Python style 'with' in C++
I am developing a simple macro that enables Python style 'with' in C++.
I have shamelessly prefixed the macro name with BOOST_ - primarily because there's a ...
6
votes
2answers
1k views
Solving the problem of using directives in a header file with a macro. Is this stupid?
I am writing some library code that is mostly templates and so is all contained in header files. I know that placing a using declaration in a header will pollute all the files that include it, but I'm ...
6
votes
1answer
106 views
Unit test macro
I have written a couple of macros (? and ??) for performing unit tests, but I'm having some difficulty with modifying it, so I ...
6
votes
1answer
175 views
C++: Generating similar methods with macros
I am currently working on a project that involves Lua. For convenience, I created a wrapper class for the Lua state structure. However, I also added some methods for getting globals and table fields. ...
6
votes
1answer
156 views
Const by default
Being a C++ developer, but also having been influenced by functional languages, I strongly believe that const should be the default for the vast majority of all ...
5
votes
3answers
75 views
Four versions of a database-creation function with different error handling
I'm starting a new, small C project and would like to have the safest, cleanest and shortest error handling code possible.
Here is a comparison of different ways to handle errors in the same C ...
5
votes
1answer
56 views
Autotools detect YAML library
I have been updating my build tools to optionally use autotools (autoconfig/automake/libtool etc.).
As part of this change I have written a couple of M4 macros. This not being something I have done ...
4
votes
3answers
244 views
Penney Game - mapping macros to strings
The SPOJ problem:
Given a 40 character string representing outcomes of 40 coin tosses,
find the frequency destribution of all the possible outcome triplets.
So, for string like : HHHH....40 Hs ,...
4
votes
2answers
742 views
A defined macro to copy selected values of std::vector to an array using std::copy
Thought I share this piece of code to the world. But be aware, I am not sure if this piece of code is safe and efficient. Feel free to improve it or give some feedback and suggestions.
...
4
votes
2answers
137 views
Efficient mechanism to generate operator overload functions
I'm attempting to tidy up a C++ framework (PyCXX).
One particular file contains ~400 lines of operator overload functions, which I've managed to reduce to the following:
...
4
votes
2answers
170 views
Macros to detect UTF-8
I'm working on a program that handles UTF-8 characters. I've made the following macros to detect UTF-8. I've tested them with a few thousand words and they seem to work.
I'll add another one to do ...
4
votes
1answer
91 views
4
votes
1answer
37 views
Introduce bindings for macro user
I'm doing the Racket track on exercism.io and solved the grains exercise:
Write a program that calculates the number of grains of wheat on a chessboard given that the number on each square doubles.
...
4
votes
1answer
432 views
AppleScript to close running processes
I've been trying to emulate MS Windows behavior on my OS X and close processes that do not have a window.
What I'd really like to do is "quit" the process on clicking the red "x" button. Instead, I'...
4
votes
2answers
113 views
Keys in mode maps
I noticed a pattern in some elisp modes I was putting together:
(let ((map (make-sparse-keymap)))
(define-key map KEY 'FN)
...
(setq FOO map))
so I wrote ...
4
votes
1answer
31 views
Saving the values of all variabled declared in a block
Often when running exprimental code to empirically investigate an algorithm, you tweak a parameter, then rerun the code, and generate a bunch of saved models for various parameters.
To make sure I ...
4
votes
2answers
44 views
Error-checking macro to jump to specified label given a failing statement
I'm starting a new C projet and I want to have the cleanest and shortest error checking code possible.
To that aim, I often use two things :
functions return 0, ...
4
votes
1answer
179 views
Generic vector implementation in C using macros
I while ago I experimented with macros in C and came up with the idea of implementing a generic vector library using macros.
This code uses the non standard typeof ...
4
votes
1answer
3k views
Qt foreach-like alternative to iterate over value AND key of an associative container
The Qt documentation recommend an iterator-based solution to iterate over an associative container like QMap and QHash, and I always wondered if there really isn't a (nice) solution using a ...
4
votes
1answer
174 views
Is this a good way to implement let-with?
I've implemented a let-with macro that takes an association list, keyed by symbols, that enables code to bind their corresponding values to local variables.
It's ...
3
votes
3answers
314 views
Use of macros to aid visual parsing of SFINAE template metaprogramming
I've recently been introduced to SFINAE to solve the problem of unwanted promotion precedence.
i.e. I was hoping to catch integer types with Foo::Foo(long) and ...
3
votes
2answers
615 views
C try/catch macros
I've created simple try/catch macros that now I'd like to promote to wider use in my projects.
I would have really liked to be able to do without global variables but I have not found any way to do ...
3
votes
2answers
206 views
C program to generate Seed programs from statically defined Befunge code
My program takes static input, and then number crunches for a few hours. I am currently using Macros, but is there a better, more "user friendly" way to do this without losing on performance.
I have ...
3
votes
1answer
28 views
Simplifying Macro-Generating Racket Macro
I'm trying to write a small macro library in Racket that extends a few of the racket/match functions I use, by printing which clause was expanded.
While this seems ...
3
votes
1answer
37 views
Custom threading macro
To help myself learn macros, I made a custom version of the threading macro that lets you choose which argument the "thread" gets put into.
My main concern is simplifying it, and making it more ...
3
votes
1answer
53 views
scope_exit macro
This is actually not something new, but I think many people wanted something useful and not incredibly complicated. So, here it is:
...
3
votes
1answer
64 views
Scale-able API development with macro definitions
In a couple of months I'll be part of a large(ish) project, and there's good chances my team will be a lot bigger, with at least 2 programmers (probably 3) and some 3-5, or more, consumers of the API ...
3
votes
1answer
73 views
in-nest-sequence: sequence generator in Racket
in-nest-sequence is a sequence generator that takes a function and an initial value, and the return value of invoking the function on the current value is used as ...
3
votes
1answer
33 views
Autotools pull in standard build system
I have been updating my build tools to optionally us autotools (autoconfig/automake/libtool etc.).
As part of this change I have written a couple of M4 macros. This not being something I have done ...
3
votes
1answer
361 views
Error-handling #ifdefs for AFNetworking requests
I am using AFNetworking 1.4.3 to send and receive network messages in iOS. My application works slightly differently in DEBUG and RELEASE mode, so I need to use ...
2
votes
2answers
69 views
C++ Minimalistic Unit Testing Library
I was looking for a unit testing library for C++, and I found many. Unfortunately, I decided I didn't want to use any of them. I decided to make my own.
This is the result. I made heavy use of the ...
