Temporary Variables: Runtime rvalue Detection

conditional expression:                                                                                                      

                 logical-or-expression                                                     

                logical-or-expression ? expression : assignment-expression

[the C++ Standard]

This operator allows you to compact an "if-then-else" statement into one single statement. Instead of writing:

if ( value==true ) { desc=”true”; } else { desc=”false”; }

You can use the ternary operator:

desc = value ? “true” : “false”;

This operator takes an expression to evaluate, then an expression to evaluate whether the condition is true and an expression to evaluate whether the condition is false. The first expression is implicitly converted to bool and if it is true, the result of the conditional expression is the second expression, otherwise that of the third expression.