[英]Pushing vector member into vector during expand: vector.push_back(vector[0])
[英]vector.push_back() produces deleted function error when pushing a thread (during compilation)
我不明白為什么,但vector<thread>.push_back()
會產生錯誤。 我嘗試用.emplace_back()
替換產生錯誤的行,但我仍然收到此錯誤。
總的來說,我的代碼試圖根據輸入顯示哪些數字是素數。 我確實知道並且已經測試過 splitString() 和 isPrime() 函數可以完美運行,只是我對 main() 的實現不正確並且在編譯時會產生錯誤。
這是我的代碼;
#include <iostream>
#include <string>
#include <cstdlib>
#include <thread>
#include <vector>
using namespace std;
bool isPrime(int number) {
int scan = number - 1;
while(scan > 1){
if(number % scan == 0){
return false;
}
scan = scan - 1;
}
return true;
}
vector<string> splitString(string String, string seperator){
vector<string> result;
size_t pos = 0;
string token;
while((pos = String.find(seperator)) != string::npos){
token = String.substr(0, pos);
result.push_back(token);
String.erase(0, pos + seperator.length());
}
result.push_back(String);
return result;
}
string getPrimes(string param){
vector<string> splitstring = splitString(param, ",");
string outstring = "";
int currentScan = stoi(splitstring[0]);
int higher = stoi(splitstring[1]);
while(currentScan <= higher){
bool res = isPrime(currentScan);
if(res == true){
outstring = outstring + to_string(currentScan) + ",";
cout << to_string(currentScan) + ",";
}
currentScan = currentScan + 1;
}
return outstring;
}
int main(int argc, char ** argv) {
int initVal = atoi(argv[0]);
int threadLength = atoi(argv[1]);
int threadCount = atoi(argv[2]);
vector<thread> threads;
int threadPart = 1;
while(threadPart <= threadCount){
int threadStart = (threadPart * threadLength) + initVal;
int threadEnd = threadStart + threadLength;
string inp = to_string(threadStart) + "," + to_string(threadEnd);
thread th(getPrimes, inp);
threads.push_back(th);
threadPart = threadPart + 1;
}
for(int i = 0; i < threads.size(); i++){
threads[i].join();
}
}
這是產生的錯誤;
In file included from C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/x86_64-w64-mingw32/bits/c++allocator.h:33,
from C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/bits/allocator.h:46,
from C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/string:41,
from C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/bits/locale_classes.h:40,
from C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/bits/ios_base.h:41,
from C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/ios:42,
from C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/ostream:38,
from C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/iostream:39,
from primes.cpp:1:
C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/ext/new_allocator.h: In instantiation of 'void __gnu_cxx::new_allocator<_Tp>::construct(_Up*, _Args&& ...) [with _Up = std::thread; _Args = {std::thread&}; _Tp = std::thread]':
C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/bits/alloc_traits.h:475:4: required from 'static void std::allocator_traits<std::allocator<_CharT> >::construct(std::allocator_traits<std::allocator<_CharT> >::allocator_type&, _Up*, _Args&& ...) [with _Up = std::thread; _Args = {std::thread&}; _Tp = std::thread; std::allocator_traits<std::allocator<_CharT> >::allocator_type = std::allocator<std::thread>]'
C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/bits/vector.tcc:103:30: required from 'void std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {std::thread&}; _Tp = std::thread; _Alloc = std::allocator<std::thread>]'
primes.cpp:55:32: required from here
C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/ext/new_allocator.h:136:4: error: use of deleted function 'std::thread::thread(std::thread&)'
{ ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from primes.cpp:4:
C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/lib/gcc/x86_64-w64-mingw32/8.1.0/include/c++/thread:109:5: note: declared here
thread(thread&) = delete;
^~~~~~
一般來說,我是 C++ 和 C 的新手。 為什么會發生這個錯誤? 我該如何解決?
似乎是因為不允許復制線程。
您可以使用threads.push_back(std::move(th));
而不是threads.push_back(th);
.
另一種選擇是使用
threads.push_back(thread(getPrimes, inp));
代替
thread th(getPrimes, inp);
threads.push_back(th);
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