C++ quick tutorial (Cheat Sheet)

Other sources

• Complete tutorial - RECOMMENDED
• C++ quick review (5min)
• Multithreading (21min)

Standard IO

• stdout: channel 1
• stderr: channel 2

Redirecting

to stdoutis:

command 1> out.txt

or command >> out.txt

to stderr is:

command 2> out.text

to both: program > out.txt 2>&1 or in different files using program 1>stdout.txt 2>stderr.txt

Chaining commands

• cmd1; cmd2 - call 1 after another
• cmd1 && cmd2 - the same as before but fails if some returns non-zero code
• cmd1 | cmd2 - piping stdout of cmd1 to stdin cmd2

Example

find smith : ls | grep smth

C++ IO streams - #include <iostream>

• std::cin - stdin
• std::cout - stdout
• std::cerr - stderr

Note

• >> in

• << out

C++ Libraries

Strings

• #include <string> to use std::string
• concatenate with +
• check if empty using str.empty()

examples:

	std::string hello = "Hello"; 
    std::cout << hello + "Bruno" << std:endl;

Arrays - Fixed size

• #include <array> to use std::array
• store collections of items of same type and fixed size: array<float3> arr = {1.0f,2.0f,3.0f}
• arr.size(); arr.clear(); arr.front(); arr.back()

Vectors - Dynamic table, usefull when you don't know the size

• #include <vector> to use std::vector
• use the same methods as array
• vec.emplace_back(value) can be more efficient than vec.push_back(value)
• to optimize vector resizing use reserve(n)
• vec.insert(,) is also available such the iterator()

C++ features

For loop

• similar to foreach() in Java, here we have for(float num: vector)

Function overloading

	string Fun(int n){return "int";}
    string Fun(const string& str){return "string";} 

Scopes

• easy example:

		float  some_float=13.3f;
        { // New inner scope
            auto another_float = some_float; // copy
        }//another_float dies

References

• Use & to state that a variable is a reference
• float& ref = original_variable; ref has type float&
• use const references as a funtion argument type for non fundamental variables types

More tips

1. CMAKE makefiles

• create folders build and src and a CMakeLists.txt file at the parent folder;

• to execute CMAKE you need to give the CMakeLists.txt path, for example build/$~ cmake .. . Follow the typical set of instructions for the project.

• To all subdirectories that we added, another CMakeLists need to exists there and they can be empty! ${PROJECT_SOURCE_DIR}/ is a system variable that is usefull to set a full path;

• At the end, we need to add a executable in the CMakeLists at src folder : add_executable(main_bin main.cpp) ; Then we can use only make at build folder unless if we added new files after making cmake. A new src folder will appear inside build folder with the executable file

from this issue :

• Tested working hotfix would be adding following lines somewhere in the head of CMakeLists.txt:

IF(APPLE)
   LINK_DIRECTORIES(/usr/local/lib)
ENDIF()

Look for libraries

arc dynamic/static libraries

use #pragama once at header files