34 lines
975 B
Plaintext
34 lines
975 B
Plaintext
= Constexpr =
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Constexpr is this great C++11 feature that marks a value or function to be
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known/executed at compile time. This is great for things likes config.hpp
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files, compile time string hashes, and more.
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== Example ==
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{{{C++
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unsigned int constexpr const_hash(char const *str){
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return *input ?
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static_cast<unsigned_int>(*input) + 33 * const_hash(input + 1) :
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5381;
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}
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void main(){
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constexpr char* const_str = "12345";
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switch(const_hash(const_str)){
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case const_hash("12345"):
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std::cout << "Found 12345\n";
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break;
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case const_hash("54321"):
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std::cout << "Found 54321\n";
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break;
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}
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}
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}}}
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Switch statements can only accept integers in C/C++, however using this we can
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convert compile time strings into integers. This is wonderful for making code
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more readable, without relying to much on C macros, which are not type aware.
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[[C++]]
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