It doesn't require knowing how a stringstream is implemented (buffer, pointer, index, etc). If you find that you need to know how a class is implemented, then either the class interface has been poorly designed, or you're just using the class wrong -- and that makes your code poorly designed. There are many other answers that "work", but they often do unnecessary copies or reallocate memory. This method only clears the values of the elements; it does not delete the elements themselves. An array has a fixed size; therefore, elements cannot be added or removed.

Clear, Stretchy Discharge: What Does It Mean? - Healthline Clear, Stretchy Discharge: What Does It Mean? - Healthline

In terms of program semantics, one may only care that the stream "appears" and "behaves" as empty, similar to how a vector::clear may leave the capacity untouched but render the vector empty to the user (of course vector would spend just 16 bytes here). Given the memory allocation that string stream requires, I can imagine this approach being often faster. This answer's primary goal is to actually clear the string stream, given that memory consumption that comes with it is no joke. Depending on your use case (number of streams, data they hold, frequency of clearing) you may choose the best approach. in std::__cxx11::basic_string, std::allocator>::reserve(unsigned long) (/usr/local/lib64/libstdc++.so.6+0x13725c) If you enable method 1 (the one shown in this answer) the extra 513 (payload) bytes are reclaimed, because the stream is actually cleared. This effectively resets m to a default constructed state, meaning that it actually deletes the buffers allocated by the string stream and resets the error state. Here's an experimental proof: int main ()Although an old question, I thought I would chime in. If I took the time to understand the question properly, I believe you wanted to clear the contents of the String and not the char array. This may help those who wanted to empty a string for other reasons. String randomString(received);

std::string::clear in C++ - GeeksforGeeks

Non-printing characters­ - strips off any of the first 32 characters in the 7-bit ASCII set (code values 0 through 31) including a tab character, line break, and so on. The following example defines a TimeZoneTime structure that includes a TimeZoneInfo field and a DateTimeOffset field. It then calls the Clear method to clear one element in a two-element array of TimeZoneTime values. The method sets the value of the cleared element to the default value of a TimeZoneInfo object, which is null, and the default value of a DateTimeOffset object, which is DateTimeOffset.MinValue. using System;

Internal error #xp20 (xp#20).

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