title: What significant exceptions are there to the zero overhead principle, if any?
body: <p>As a (possible) example, the LLVM coding standard forbids using standard RTTI or exceptions:
  <a href="http://llvm.org/docs/CodingStandards.html#do-not-use-rtti-or-exceptions" rel="nofollow">http://llvm.org/docs/CodingStandards.html#do-not-use-rtti-or-exceptions</a></p>
  
  <p>Is this a good idea, or is that coding standard outdated or unreasonable for most programs?  </p>
  
  <p>Are there any other such features in C++ which significantly worsen the program's speed, memory usage or executable size even if you don't use them?</p>