All Questions
49,009
questions
-4
votes
0
answers
64
views
how often do you use the noexcept or constexpr modifier [closed]
how often do you use the noexcept or constexpr modifier in real work? Scott Myers wrote a lot about the importance of these structures, but why in practice I rarely saw this with my colleagues, share ...
-4
votes
0
answers
89
views
Which C++ string type should I migrate to? [closed]
I see so many options for C++ string types, like:
std::string
std::u16string
std::u8string
CString
Platform::String
wchar_t
char
Narrowing this down a bit, my 3 options seem to be:
std::string - ...
-1
votes
1
answer
55
views
External Data Structure Used in Custom Comparison Function in C++ [duplicate]
I have array of numbers and I have to sort them based on there frequency in ascending order
and if both numbers are same then sort them in decreasing order
what I did was I create unordered_map and ...
1
vote
3
answers
128
views
Behaviour of std::is_sorted function in C++
Consider the following C++ program which checks whether the given array is sorted or not.
#include <iostream>
#include <vector>
#include <algorithm>
int main()
{
std::vector<...
- 999
-3
votes
1
answer
71
views
count the maximum number of triangles made up of a sequence of numbers Two triangles are called the same if they have 3 pairs of sides equally [closed]
WE HAVE A ARRAY: 2 3 3 4 4 4 6 6 6 6
Maximum number of triangles formed: 12
BECAUSE:
(4, 4, 4) 4) (4, 4, 2) (4, 4, 3) (4, 4, 6) (6, 6,
2) (6, 6, 3) (6, 6, 4) (2, 3, 4) (3, 4, 6)
(6, 6, 6) (3, 3, 2) (3,...
-1
votes
0
answers
97
views
why std::move(std::vector<int>) does not move [duplicate]
I'm really confused cause of C++ having so many "unspecified states". In the code below, I'm trying to move std::vector to a set(&&) function, but the output seems like it's not ...
- 731
-1
votes
2
answers
56
views
C++ Rectangle 2D Array with numbers beside the rectangle
I've been trying to make a 2D array of rectangle, and i want the number of index x to printed beside the rectangle and index y to be printed below the rectangle..
Here is my code..
int height, width;
...
- 1
-2
votes
0
answers
75
views
Undefined reference to std::string while linking, but the header doesn't seem to be the problem [duplicate]
I am translating a program that was written in C to C++. It was as easy as changing the suffix to the file and modifying some compiler flags. Before using actual C++ features, it compiled perfectly.
...
1
vote
1
answer
118
views
Two almost similar multithreaded code have very different running time
i am having a strange problem for C++ multithreaded programs.
i wrote the first code and was not seeing any performance improvement over single threaded code.
i kept on experimenting with shifting the ...
1
vote
2
answers
109
views
Why exception can not be caught on windows by msvc but on Linux by GCC [duplicate]
The same files on Windows and Linux as follow:
std_exp.cpp
#include <iostream>
#include <string>
#include <stdexcept>
using namespace std;
int main() {
try {
std::...
-3
votes
1
answer
71
views
Understanding usage of std::for_each with structs [duplicate]
I am trying to understand how below code works, from cpp reference website:
std::vector<int> v{3, -4, 2, -8, 15, 267};
struct Sum
{
void operator()(int n) { sum += n; }
int sum {0};
};
...
- 111
0
votes
0
answers
61
views
Templating CUDA
CUDA supports templates and that is nice, I have however problem with interplay with C++.
Let's say I have functions
template <typename T>
void CUDAZeroPad2D(dim3 threads,
...
- 610
0
votes
0
answers
61
views
Right memory_order to react on atomic increment changes in other thread?
Consider such code:
#include <atomic>
#include <thread>
bool read_from_network() noexcept;
void write_to_network() noexcept;
int main() {
std::atomic<size_t> work_counter;
std:...
- 7,932
0
votes
1
answer
63
views
Guarding tests against exit/death
I'm using googletest to test multi-threading code with std::thread. In broken code, it often happens that a std::thread is destroyed before the thread has joined, causing a program termination. ...
- 567
4
votes
2
answers
118
views
Idiomatic ways of using tuples and std::tie
I am trying to implement the modular multiplicative inverse using the extended Euclidean algorithm in C++. In Python, the code for this is concise and idiomatic, using tuple unpacking:
def inv_modulo(...
- 1,338