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copied!<p>Yes.</p> <p>Built-in logical AND (<code>&&</code>), logical OR (<code>||</code>) and the comma operator (<code>,</code>) are the <strong>only</strong> cases in which for a binary operator C++ guarantees that evaluation will compute left expression and then (if not short circuited) right expression (comma operator of course always evaluates both operands, first left and then right).</p> <p>Note also that the comma between function arguments is not a comma operator and therefore the order of evaluation of function arguments is not specified and even worse than that: for example in <code>f(g(h()),i())</code> it is possible that the sequence of calls will be <code>h,i,g,f</code>.</p> <p>Also the guarantee about evaluation order only applies to built-in operators; if you redefine them then they basically become function calls where the order of evaluation of arguments is not guaranteed and where short-circuiting is not performed.</p> <p>Other binary operators don't guarantee the order of evaluation and for example one common mistake is to think that in:</p> <pre><code>std::cout << foo() << bar(); </code></pre> <p>the call to <code>foo()</code> is guaranteed to happen before the call to <code>bar()</code> ... this is <strong>not</strong> true.</p> <p>Of course the order of evaluation is also guaranteed for the <strong>ternary</strong> <code>:?</code> operator, where only one of the two other expressions will be evaluated after first evaluating the condition.</p> <p>Another place in which the order of evaluation is guaranteed (and sometimes surprising for newbies) is member initialization lists for constructors, but in this case the order is <strong>not</strong> the one in the expression, but the order of member declaration in the class.... for example:</p> <pre><code>struct Foo { int x, y; Foo() : y(compute_y()), x(compute_x()) {} }; </code></pre> <p>in this case it is <strong>guaranteed</strong> that the call <code>compute_x()</code> will be done BEFORE the call <code>compute_y()</code> because <code>x</code> precedes <code>y</code> in the member declarations.</p>

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