How to remove accents and tilde in a C++ std::string

Question

I have a problem with a string in C++ which has several words in Spanish. This means that I have a lot of words with accents and tildes. I want to replace them for their not

Answer 1

I disagree with the currently "approved" answer. The question makes perfect sense when you are indexing text. Like case-insensitive search, accent-insensitive search is a good idea. "naïve" matches "Naïve" matches "naive" matches "NAİVE" (you do know that an uppercase i is İ in Turkish? That's why you ignore accents)

Now, the best algorithm is hinted at the approved answer: Use NKD (decomposition) to decompose accented letters into the base letter and a seperate accent, and then remove all accents.

There is little point in the re-composition afterwards, though. You removed most sequences which would change, and the others are for all intents and purposes identical anyway. WHat's the difference between æ in NKC and æ in NKD?