What's the purpose of using braces (i.e. {}) for a single-line if or loop?

Question

I\'m reading some lecture notes of my C++ lecturer and he wrote the following:

1. Use Indentation // OK
2. Never rely on operator preced

Answer 1

The codebase I'm working on is scattered with code by people with a pathological aversion to braces, and for the people who come along later, it really can make a difference to maintainability.

The most frequent problematic example I have encountered is this:

if ( really incredibly stupidly massively long statement that exceeds the width of the editor) do_foo;
    this_looks_like_a_then-statement_but_isn't;

So when I come along and wish to add a then-statement, I can easily end up with this if I'm not careful:

if ( really incredibly stupidly massively long statement that exceeds the width of the editor) do_foo;
{
    this_looks_like_a_then-statement_but_isn't;
    i_want_this_to_be_a_then-statement_but_it's_not;
}

Given that it takes ~1second to add braces and can save you at minimum a few confused minutes debugging, why would you ever not go with the reduced-ambiguity option? Seems like false economy to me.