cheat hud c++ code example

Example 1: C++ CHEAT SHEAT

#include <future>         // Include future
function<int(int)> fib =  // Create lambda function
  [&](int i){
    if (i <= 1){
      return 1;
    }
    return fib(i-1) 
         + fib(i-2);
  };
future<int> fut =         // result of async function
  async(launch::async, fib, 4); // start async function in other thread
// do some other work 
cout << fut.get();        // get result of async function. Wait if needed.

Example 2: c++ cheat sheet

x=y;                        // Every expression is a statement
int x;                      // Declarations are statements
;                           // Empty statement
{                           // A block is a single statement
    int x;                  // Scope of x is from declaration to end of block
}
if (x) a;                   // If x is true (not 0), evaluate a
else if (y) b;              // If not x and y (optional, may be repeated)
else c;                     // If not x and not y (optional)

while (x) a;                // Repeat 0 or more times while x is true

for (x; y; z) a;            // Equivalent to: x; while(y) {a; z;}

for (x : y) a;              // Range-based for loop e.g.
                            // for (auto& x in someList) x.y();

do a; while (x);            // Equivalent to: a; while(x) a;

switch (x) {                // x must be int
    case X1: a;             // If x == X1 (must be a const), jump here
    case X2: b;             // Else if x == X2, jump here
    default: c;             // Else jump here (optional)
}
break;                      // Jump out of while, do, or for loop, or switch
continue;                   // Jump to bottom of while, do, or for loop
return x;                   // Return x from function to caller
try { a; }
catch (T t) { b; }          // If a throws a T, then jump here
catch (...) { c; }          // If a throws something else, jump here