Building Blockchain Projects

Using for

The using A for B; directive can be used to attach library functions (from the library A to any type B). These functions will receive the object they are called on as their first parameter.

The effect of using A for *; is that the functions from the library A are attached to all types.

Here is an example to demonstrate for:

library math {     struct myStruct1 {         int a;     }     struct myStruct2 {         int a;     }     //Here we have to make 's' location storage so that we get a reference.      //Otherwise addInt will end up accessing/modifying a different instance of myStruct1 than the one on which its invoked     function addInt(myStruct1 storage s, int b) returns (int c)     {         return s.a + b;     }  function subInt(myStruct2 storage s, int b) returns (int ...