Why should one use std::string over c-style strings in C++?

Question

\"One should always use std::string over c-style strings(char *)\" is advice that comes up for almost every source code posted here. While the

Answer 1

Why should one use std::string over c-style strings in C++?

The main reason is it frees you from managing the lifetime of the string data. You can just treat strings as values and let the compiler/library worry about managing the memory.

Manually managing memory allocations and lifetimes is tedious and error prone.

What are the disadvantages (if any) of the practice mentioned in #1?

You give up fine-grained control over memory allocation and copying. That means you end up with a memory management strategy chosen by your toolchain vendor rather than chosen to match the needs of your program.

If you aren't careful you can end up with a lot of unneeded data copying (in a non-refcounted implementation) or reference count manipulation (in a refcounted implementation)

In a mixed-language project any function whose arguments use std::string or any data structure that contains std::string will not be able to be used directly from other languages.

What are the scenarios where the opposite of the advice mentioned in #1 is a good practice?

Different people will have different opinions on this but IMO

• For function arguments passing strings in "const char *" is a good choice since it avoids unnessacery copying/refcouning and gives the caller flexibility about what they pass in.
• For things used in interoperation with other languages you have little choice but to use c-style strings.
• When you have a known length limit it may be faster to use fixed-size arrays.
• When dealing with very long strings it may be better to use a construction that will definately be refcounted rather than copied (such as a character array wrapped in a shared_ptr) or indeed to use a different type of data structure altogether