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c++ - Difference between | and || , or & and && - Stack Overflow
Dec 28, 2015 · Closed 9 years ago. These are two simple samples in C++ written on Dev-cpp C++ 5.4.2:
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What is the <=> ("spaceship", three-way comparison) operator in...
Nov 24, 2017 · This is called the three-way comparison operator. According to the P0515 paper proposal: There’s a new three-way comparison operator, . The expression a b returns an object that compares 0 if a > b, and...
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What is the purpose of using #ifdef and #if in C++?
The meaning of #ifdef is that the code inside the block will be included in the compilation only if the mentioned preprocessor macro is defined. Similarly, #if means that the block will be included only if the express...
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What is the C++ function to raise a number to a power?
In C++ the "^" operator is a bitwise XOR. It does not work for raising to a power. The x << n is a left shift of the binary number which is the same as multiplying x by 2 n number of times and that can only be used wh...
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How can I convert int to string in C++? - Stack Overflow
itoa will be faster than the stream equivalent. There are also ways of re-using the string buffer with the itoa method (avoiding heap allocations if you are frequently generating strings. e.g. for some rapidly updatin...
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C++ code file extension? What is the difference between .cc and...
95 .cpp is the recommended extension for C++ as far as I know. Some people even recommend using .hpp for C++ headers, just to differentiate from C. Although the compiler doesn't care what you do, it's personal preference.
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What is the meaning of the auto keyword? - Stack Overflow
32 For variables, specifies that the type of the variable that is being declared will be automatically deduced from its initializer. For functions, specifies that the return type is a trailing return type or will be d...
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c++ - How can I trim a std::string? - Stack Overflow
} // The remaining functions (trim() et al.) are identical to the new C++11 version std::ptr_fun is needed to disambiguate std::isspace because there is a second definition which supports locales. This could have been...
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Proper way to initialize C++ structs - Stack Overflow
Jan 21, 2017 · Our code involves a POD (Plain Old Datastructure) struct (it is a basic c++ struct that has other structs and POD variables in it that needs to get initialized in the beginning.) Based one what I...
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How to find if a given key exists in a std::map - Stack Overflow
To those who are looking for speed: count and find are nearly identical in speed when using maps that require unique keys. (1) If you don't need the elements to maintain a specific order, use std::unordered_map, which...