<!-- @example.append('''
    return s3;
}

std::string x = f((_s1="hello,", _s2=" world", _s3="hi world"));

int main()
{}''') -->
<!-- @test('run') -->
<!-- .. _Lambda: ../../../lambda/index.html -->
<div class="sidebar">
<p class="first sidebar-title">Mnemonics</p>
<p class="last">To remember the difference between <tt class="docutils literal">|</tt> and <tt class="docutils literal">||</tt>, recall that
<tt class="docutils literal">||</tt> normally uses short-circuit evaluation: its second
argument is onl