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How to define a preprocessor symbol in Xcode
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As an addendum, if you are using this technique to define strings in your target, this is how I had to define and use them:
In Build Settings -> Preprocessor Macros, and yes backslashes are critical in the definition:
APPURL_NSString=\@\"www.foobar.org\"
And in the source cod...
Is it better in C++ to pass by value or pass by constant reference?
...or large objects that implement proper move constructors (such as vectors, strings …), the second case is then vastly more efficient than the first. Therefore, it is recommended to use pass by value if the function takes ownership of the argument, and if the object type supports efficient moving.
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What is the purpose of std::make_pair vs the constructor of std::pair?
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int main() {
MyClass<int> my_class(1);
}
then:
g++-8 -Wall -Wextra -Wpedantic -std=c++17 main.cpp
compiles happily, but:
g++-8 -Wall -Wextra -Wpedantic -std=c++14 main.cpp
fails with:
main.cpp: In function ‘int main()’:
main.cpp:13:13: error: missing template arguments before...
uint8_t vs unsigned char
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@endolith, using uint8_t for a string isn't necessarily wrong, but it's definitely weird.
– Mark Ransom
Nov 14 '11 at 13:58
5
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Pretty-print C++ STL containers
... that match those criteria but aren't actually containers, like std::basic_string. Also like Marcelo's version, it uses templates that can be specialized to specify the delimiters to use.
The major difference is that I've built my version around a pretty_ostream_iterator, which works similar to the...
In STL maps, is it better to use map::insert than []?
...y create:
using std::cout; using std::endl;
typedef std::map<int, std::string> MyMap;
MyMap map;
// ...
std::pair<MyMap::iterator, bool> res = map.insert(MyMap::value_type(key,value));
if ( ! res.second ) {
cout << "key " << key << " already exists "
<...
What is the use of the %n format specifier in C?
... Oh my - this is a character-based version of computing the pixel size of string in a given font!
– user3458
Aug 4 '10 at 12:41
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Fastest way to flatten / un-flatten nested JSON objects
...d more speed out of your implementation by replacing the regex.exec() with string.split() and simplifying the key format. I'll give it a few days before I award you the pts, but I think the 'wall of meaningful optimization' has been reached.
– Louis Ricci
Oct 5...
How do I do base64 encoding on iOS?
...or Objective C categories.
For Base64 encoding:
#import <Foundation/NSString.h>
@interface NSString (NSStringAdditions)
+ (NSString *) base64StringFromData:(NSData *)data length:(int)length;
@end
-------------------------------------------
#import "NSStringAdditions.h"
static char base...
Sanitizing strings to make them URL and filename safe?
...ying to come up with a function that does a good job of sanitizing certain strings so that they are safe to use in the URL (like a post slug) and also safe to use as file names. For example, when someone uploads a file I want to make sure that I remove all dangerous characters from the name.
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