mirror of git://git.qorg11.net/kill9.git
14 KiB
14 KiB
C++ sucks
C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg.
--- Bjarne Stroustrup
If you like C++, you don’t know C++. There’s a mutual exclusion going on here, and I’ve yet to see a counter-example other than possibly a few of the members of the standards committee.
--- ssylvan
I think maybe the guy who invented C++ doesn’t know the difference between increment and excrement.
--- smcameron
I invented the term object oriented, and I can tell you that C++ wasn't what I had in mind.
--- Alan Kay
Object oriented
So automatically sucks.
Ugly syntax
The only non-ugly part of C++ is the headers' name: iostream, cmath, ctime, thread, etc. Unlike in C, where they are ugly as shit: stdio.h, unistd.h, stdlib.h, pthreads.h...
But the rest of the language has the ugliest syntax that I've ever seen:
Hello world in C++
#include <iostream>
int main(void)
{
std::cout << "Hello world!" << std:endl;
}
What the FUCK was Bjarne smoking when he did this:
In C:
printf("0x%04x\n", 0x424);
In C++:
std::cout << "0x" << std::hex << std::setfill('0') << std::setw(4) << 0x424 << std::endl;
Now what the fuck is std:: and why do I have to write << just to print some shit.
Note: you can skip the std:: part with using namespace std but this is a bad practice
Error messages
in the following code:
#include <iostream>
int main(void)
{
std::cout < "Hello world!" < std:endl;
}
You get this error message:
a.cc: In function ‘int main()’:
a.cc:5:13: error: no match for ‘operator<’ (operand types are ‘std::ostream’ {aka ‘std::basic_ostream<char>’} and ‘const char [13]’)
5 | std::cout < "Hello world!" < std:endl;
| ~~~~~~~~~ ^ ~~~~~~~~~~~~~~
| | |
| | const char [13]
| std::ostream {aka std::basic_ostream<char>}
In file included from /usr/local/include/c++/10.0.1/bits/stl_algobase.h:64,
from /usr/local/include/c++/10.0.1/bits/char_traits.h:39,
from /usr/local/include/c++/10.0.1/ios:40,
from /usr/local/include/c++/10.0.1/ostream:38,
from /usr/local/include/c++/10.0.1/iostream:39,
from a.cc:1:
/usr/local/include/c++/10.0.1/bits/stl_pair.h:489:5: note: candidate: ‘template<class _T1, class _T2> constexpr bool std::operator<(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)’
489 | operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
| ^~~~~~~~
/usr/local/include/c++/10.0.1/bits/stl_pair.h:489:5: note: template argument deduction/substitution failed:
a.cc:5:15: note: ‘std::ostream’ {aka ‘std::basic_ostream<char>’} is not derived from ‘const std::pair<_T1, _T2>’
5 | std::cout < "Hello world!" < std:endl;
| ^~~~~~~~~~~~~~
In file included from /usr/local/include/c++/10.0.1/bits/stl_algobase.h:67,
from /usr/local/include/c++/10.0.1/bits/char_traits.h:39,
from /usr/local/include/c++/10.0.1/ios:40,
from /usr/local/include/c++/10.0.1/ostream:38,
from /usr/local/include/c++/10.0.1/iostream:39,
from a.cc:1:
/usr/local/include/c++/10.0.1/bits/stl_iterator.h:366:5: note: candidate: ‘template<class _Iterator> bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)’
366 | operator<(const reverse_iterator<_Iterator>& __x,
| ^~~~~~~~
/usr/local/include/c++/10.0.1/bits/stl_iterator.h:366:5: note: template argument deduction/substitution failed:
a.cc:5:15: note: ‘std::ostream’ {aka ‘std::basic_ostream<char>’} is not derived from ‘const std::reverse_iterator<_Iterator>’
5 | std::cout < "Hello world!" < std:endl;
| ^~~~~~~~~~~~~~
In file included from /usr/local/include/c++/10.0.1/bits/stl_algobase.h:67,
from /usr/local/include/c++/10.0.1/bits/char_traits.h:39,
from /usr/local/include/c++/10.0.1/ios:40,
from /usr/local/include/c++/10.0.1/ostream:38,
from /usr/local/include/c++/10.0.1/iostream:39,
from a.cc:1:
/usr/local/include/c++/10.0.1/bits/stl_iterator.h:404:5: note: candidate: ‘template<class _IteratorL, class _IteratorR> bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)’
404 | operator<(const reverse_iterator<_IteratorL>& __x,
| ^~~~~~~~
/usr/local/include/c++/10.0.1/bits/stl_iterator.h:404:5: note: template argument deduction/substitution failed:
a.cc:5:15: note: ‘std::ostream’ {aka ‘std::basic_ostream<char>’} is not derived from ‘const std::reverse_iterator<_Iterator>’
5 | std::cout < "Hello world!" < std:endl;
| ^~~~~~~~~~~~~~
In file included from /usr/local/include/c++/10.0.1/bits/stl_algobase.h:67,
from /usr/local/include/c++/10.0.1/bits/char_traits.h:39,
from /usr/local/include/c++/10.0.1/ios:40,
from /usr/local/include/c++/10.0.1/ostream:38,
from /usr/local/include/c++/10.0.1/iostream:39,
from a.cc:1:
/usr/local/include/c++/10.0.1/bits/stl_iterator.h:1451:5: note: candidate: ‘template<class _IteratorL, class _IteratorR> bool std::operator<(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)’
1451 | operator<(const move_iterator<_IteratorL>& __x,
| ^~~~~~~~
/usr/local/include/c++/10.0.1/bits/stl_iterator.h:1451:5: note: template argument deduction/substitution failed:
a.cc:5:15: note: ‘std::ostream’ {aka ‘std::basic_ostream<char>’} is not derived from ‘const std::move_iterator<_IteratorL>’
5 | std::cout < "Hello world!" < std:endl;
| ^~~~~~~~~~~~~~
In file included from /usr/local/include/c++/10.0.1/bits/stl_algobase.h:67,
from /usr/local/include/c++/10.0.1/bits/char_traits.h:39,
from /usr/local/include/c++/10.0.1/ios:40,
from /usr/local/include/c++/10.0.1/ostream:38,
from /usr/local/include/c++/10.0.1/iostream:39,
from a.cc:1:
/usr/local/include/c++/10.0.1/bits/stl_iterator.h:1507:5: note: candidate: ‘template<class _Iterator> bool std::operator<(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)’
1507 | operator<(const move_iterator<_Iterator>& __x,
| ^~~~~~~~
/usr/local/include/c++/10.0.1/bits/stl_iterator.h:1507:5: note: template argument deduction/substitution failed:
a.cc:5:15: note: ‘std::ostream’ {aka ‘std::basic_ostream<char>’} is not derived from ‘const std::move_iterator<_IteratorL>’
5 | std::cout < "Hello world!" < std:endl;
| ^~~~~~~~~~~~~~
In file included from /usr/local/include/c++/10.0.1/string:55,
from /usr/local/include/c++/10.0.1/bits/locale_classes.h:40,
from /usr/local/include/c++/10.0.1/bits/ios_base.h:41,
from /usr/local/include/c++/10.0.1/ios:42,
from /usr/local/include/c++/10.0.1/ostream:38,
from /usr/local/include/c++/10.0.1/iostream:39,
from a.cc:1:
/usr/local/include/c++/10.0.1/bits/basic_string.h:6267:5: note: candidate: ‘template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)’
6267 | operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
| ^~~~~~~~
/usr/local/include/c++/10.0.1/bits/basic_string.h:6267:5: note: template argument deduction/substitution failed:
a.cc:5:15: note: ‘std::ostream’ {aka ‘std::basic_ostream<char>’} is not derived from ‘const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>’
5 | std::cout < "Hello world!" < std:endl;
| ^~~~~~~~~~~~~~
In file included from /usr/local/include/c++/10.0.1/string:55,
from /usr/local/include/c++/10.0.1/bits/locale_classes.h:40,
from /usr/local/include/c++/10.0.1/bits/ios_base.h:41,
from /usr/local/include/c++/10.0.1/ios:42,
from /usr/local/include/c++/10.0.1/ostream:38,
from /usr/local/include/c++/10.0.1/iostream:39,
from a.cc:1:
/usr/local/include/c++/10.0.1/bits/basic_string.h:6280:5: note: candidate: ‘template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)’
6280 | operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
| ^~~~~~~~
/usr/local/include/c++/10.0.1/bits/basic_string.h:6280:5: note: template argument deduction/substitution failed:
a.cc:5:15: note: ‘std::ostream’ {aka ‘std::basic_ostream<char>’} is not derived from ‘const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>’
5 | std::cout < "Hello world!" < std:endl;
| ^~~~~~~~~~~~~~
In file included from /usr/local/include/c++/10.0.1/string:55,
from /usr/local/include/c++/10.0.1/bits/locale_classes.h:40,
from /usr/local/include/c++/10.0.1/bits/ios_base.h:41,
from /usr/local/include/c++/10.0.1/ios:42,
from /usr/local/include/c++/10.0.1/ostream:38,
from /usr/local/include/c++/10.0.1/iostream:39,
from a.cc:1:
/usr/local/include/c++/10.0.1/bits/basic_string.h:6292:5: note: candidate: ‘template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const _CharT*, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)’
6292 | operator<(const _CharT* __lhs,
| ^~~~~~~~
/usr/local/include/c++/10.0.1/bits/basic_string.h:6292:5: note: template argument deduction/substitution failed:
a.cc:5:15: note: mismatched types ‘const _CharT*’ and ‘std::basic_ostream<char>’
5 | std::cout < "Hello world!" < std:endl;
| ^~~~~~~~~~~~~~
In file included from /usr/local/include/c++/10.0.1/bits/ios_base.h:46,
from /usr/local/include/c++/10.0.1/ios:42,
from /usr/local/include/c++/10.0.1/ostream:38,
from /usr/local/include/c++/10.0.1/iostream:39,
from a.cc:1:
/usr/local/include/c++/10.0.1/system_error:252:3: note: candidate: ‘bool std::operator<(const std::error_code&, const std::error_code&)’
252 | operator<(const error_code& __lhs, const error_code& __rhs) noexcept
| ^~~~~~~~
/usr/local/include/c++/10.0.1/system_error:252:31: note: no known conversion for argument 1 from ‘std::ostream’ {aka ‘std::basic_ostream<char>’} to ‘const std::error_code&’
252 | operator<(const error_code& __lhs, const error_code& __rhs) noexcept
| ~~~~~~~~~~~~~~~~~~^~~~~
/usr/local/include/c++/10.0.1/system_error:379:3: note: candidate: ‘bool std::operator<(const std::error_condition&, const std::error_condition&)’
379 | operator<(const error_condition& __lhs,
| ^~~~~~~~
/usr/local/include/c++/10.0.1/system_error:379:36: note: no known conversion for argument 1 from ‘std::ostream’ {aka ‘std::basic_ostream<char>’} to ‘const std::error_condition&’
379 | operator<(const error_condition& __lhs,
| ~~~~~~~~~~~~~~~~~~~~~~~^~~~~
a.cc:5:35: error: found ‘:’ in nested-name-specifier, expected ‘::’
5 | std::cout < "Hello world!" < std:endl;
| ^
| ::
Objects are stupid
std::string spurdo = "sparde"
where spurdo is an object
spurdo.c_str() // converts the string to a C '\0' terminated string.
In C, strings are an array of chars, in C++, they're an object, with methods.
Compatibilty
C++ is "compatible" with C
But this can break most C programs
A sad story about c++ executables
<lucy> try to strip the executable
<lucy> Did it change anything?
<qorg11> strip?
<lucy> "strip a.out"
<lucy> It removes unused stuff
<lucy> like debug symbols and similar
<qorg11> qorg@satania ~> md5sum a.out
cd1cc93ac2ea0c8129042e96ae7d65e7 a.out
qorg@satania ~> strip a.out
qorg@satania ~> md5sum a.out
e6e6e1ea132edb67c6005e703ebe7c81 a.out
<qorg11> yeah?
<lucy> and now compare the assembly code
<qorg11> how
<qorg11> do i disassembly it or what
<lucy> how did you do it before?
<qorg11> g++ -S
<qorg11> lol
<lucy> oof
<lucy> maybe just compare the filesize
<qorg11> qorg@satania ~> gcc mtx.c -lcurses -lpthread
qorg@satania ~> du -h a.out
24K a.out
<qorg11> qorg@satania ~> g++ mtx.cc -lcurses -pthread
qorg@satania ~> du -h a.out
40K a.out
<qorg11> now with -Os
<qorg11> qorg@satania ~> gcc mtx.c -lcurses -lpthread -Os
qorg@satania ~> du -h a.out
24K a.out
<qorg11> lol
<qorg11> qorg@satania ~> g++ mtx.cc -lcurses -pthread -Os
qorg@satania ~> du -h a.out
24K a.out
<qorg11> congrats c++!
<qorg11> exact filesize: 23488 (according to stat)
<lucy> now the stripped versions
<qorg11> stat'd c version: 21520
<qorg11> stripped c++ 14680
<qorg11> stripped c: 14472
<lucy> a considerably smaller difference
<lucy> So c++ is bloated up with debug symbols, awesome
<qorg11> lol
<qorg11> can i take a log of this and put it in kill-9.xyz/harmful/software/c++?