I need to place two dependent init statements within one if condition. As a raw example:

if (bool x = false; bool y = true) std::cout << "Check!\n";

The whole expression evaluates to true, and that is the problem. Suppose I want to test a pointer in the first statement and dereference this pointer to test something else in the second statement:

if (auto ptr = ptr_to_check; auto sth_else = ptr_to_check->sth_else()) { /* do something */ }

And this one is going to crash as I can still dereference nullptr. I want to avoid nested if's as in my program there are other statements nested within this one. Can I place these two statements within one condition somehow?

CodePudding user response：

When it comes to several statements within one if, only the last statement is evaluated as a condition. In this case, a ternary operator is a solution:

if (bool x = false; bool y = x ? true : false) std::cout << "Check!\n";

So, in case of pointers:

if (auto ptr = ptr_to_check; auto sth_else = ptr_to_check ? ptr_to_check->sth_else() : sth_evaluating_to_false) { /* do something */ }