[PixyMisa]

4) string concatenation

[piker]

Probably (1) above, no?

[pjmlp]

NULL terminated strings are quite bad for performance, because you need to transverse them to find the terminator.

Now try to concatenate a bunch of them in C.

[varajelle]

C++ code usually use std:: string, std::string_view, or other string classes that stores the string size and has some capacity pre-allocated to avoid such issues.

[zlynx]

Profiling is essential. I found a performance bug in calling some C++ functions a while ago, because they accepted a const std::string& and were being called in loops with a C const char*. Every single call had to construct a std::string involving a strlen, allocation and copy.

std::string_view is a nice fix for this but few programmers seem to use it yet.

[pjmlp]

The (1) also mentions C.

I would partially agree with you, if it only mentioned C++.

Only partially, because too many C++ devs still use plain old C strings.

[astrobe_]

Like this ?

    const char* strings[]={"ab","cd", "ef", "gh", ....};
    char result[1024*1024*1024*1024];
    size_t sz=0;
    for(int i=0; i<sizeof(strings); i++)
    { size_t len=strlen(strings[i]); memcpy(result+sz, strings[i], len); sz+=len; }
    result[sz]=0;

[harveywi]

>you need to traverse them to find the terminator.

Why not just do a binary search through the entire 256TB virtual memory space, finding the largest memory address that doesn't segfault? :-)