Questions tagged [c++17]
C++17 is the version of C++ after C++14. This tag should be used (along with the [C++] tag) for questions about C++ features specific to C++17
c++17
11,132
questions
0
votes
0
answers
25
views
Extension of lifetime for inner fields when the type's lifetime is extended?
I am pondering about a piece of tooling code that we were using for a while here now, but which I suspect is actual undefined behaviour (at least, I got a couple of debugging sessions where it looks ...
0
votes
0
answers
118
views
const char* vs std::string_view for constants [closed]
I usually use constexpr const char* for defining string constants. Of late, I have been noticing that std::string_view is very popular for this purpose. Which of these is the best?
// 1. char pointer
...
- 437
-3
votes
1
answer
50
views
Optimize memory in operators overload and template structures
The task:
In this task you have to write a structure that will work both like a regular array in C and like a list in Python. Namely, write a structure
template<typename T>
struct FlexArray;
...
1
vote
0
answers
33
views
Unable to include thrust/host_vector.h and others with CUDA 12.5
This test program compiled fine with CUDA 12.4 and lower, but fails to compile w/ 12.5.1:
#include <thrust/host_vector.h>
#include <thrust/scan.h>
#include <iostream>
int main() {
...
- 20.6k
-1
votes
0
answers
50
views
<wx/wxprec.h> file not found [duplicate]
I've been trying to learn C++ and I started to learn about GUIs, but I've encountered some problems.
I am using wxWidgets 3.2.5, downloaded it by source on the official website but I can't get It to ...
- 19
1
vote
1
answer
26
views
How to use void for std::conditional_t in C++17
I try to define the std::function template arguments of a class member based on a std::conditional_t type:
template <class T, size_t N = 1>
class MyClass {
static_assert( (N > 0), "0 ...
- 518
1
vote
1
answer
80
views
How do I use std::reference_wrapper to store the reference in an std::unordered_map?
I'm trying to learn the use of std::reference_wrapper and std::ref and the use cases of it.
Here is a sample code I wrote. Please help me solve the compilation error. And it would be great if you can ...
- 13
-1
votes
1
answer
80
views
JNI CallStaticObjectMethod is causing crash with Java 21
The company I work for recently moved to Java 21 from Java 8, which updated the JNI version as well that is used with interoperatibility with C++. All the function (written in C++) called through JNI ...
- 346
-1
votes
0
answers
47
views
Matplot++- dealing with linker errors as a novice
I have installed matplot++ using vcpkg and compiled it with c++17. Working in visual studio 2022, I tried to copy a basic example from its github:
#include <cmath>
#include <matplot/matplot.h&...
- 117
1
vote
1
answer
80
views
What is error: expected unqualified-id before ‘(’ token?
I clone this open source project https://github.com/balfieri/cordic. I encountered issue below after following README to run $ g++ -std=c++17 -o test_basic test_basic.cpp
$ g++ -std=c++17 -o ...
- 51
1
vote
0
answers
69
views
Argument passing and dangling pointers [duplicate]
I know that, in general, when calling a function, the evaluation of the arguments of the function call can happen in any order, but I'm in doubt about this particular situation (imagine T has a move ...
- 11.4k
1
vote
1
answer
90
views
Does early return of the same variable prevent NRVO?
Here is the code:
std::vector<int> foo(bool cond) {
std::vector<int> result;
if (cond) {
return result; // (1)
}
result.push_back(42);
return result; ...
- 6,435
4
votes
1
answer
110
views
correct syntax to access a template variable specialization
assume a template variable in data.h:
template <class T>
struct Data
{
Data() = delete;
Data(T initValue) : value(initValue){}
T value;
};
template<class T>
extern Data<T&...
- 758
-2
votes
1
answer
50
views
C++ a single place to keep all #includes?
Gets a bit complicated with all #includes within each CPP file, is there a single place to keep all #includes?
- 27
2
votes
2
answers
63
views
Partial specialization of a class for pointer to members
I'm trying to create a function object where, given a pointer to a member, it calls std::hash of the pointed-to member (or the result of calling the function member), but there's something wrong about ...
- 11.4k