Question

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behaviour of const_cast

I need to understand what this line means

char A = strdup(const_cast<char*>(aString.c_str()));

I understand what strdup does from this:

strdup() – what does it do in C?

strdup expects a const char pointer. Its the <,> part of the above line that confuses me.

Answer 1

const_cast< type > is a C++ operator. You can read about it here.

I don’t understand why it’s needed here, since (assuming aString is of type std::string) c_str() already returns the const char* which strdup requires, and in any case adding constness is done implicitly.

Only if the function receives a non-const parameter it’s required, and even then it’s usually not recommended.