我尝试实现lambda函数:-
vector<int> numbers;
int value = 0;
cout << "Pushing back...n";
while (value >= 0) {
cout << "Enter number: ";
cin >> value;
if (value >= 0)
numbers.push_back(value);
}
print( [numbers]() ->
{
cout << "Vector content: { ";
for (const int& num : numbers)
cout << num << " ";
cout << "}nn";
});
我得到一个错误:-
1.Severity Code Description Project File Line Source Suppression State
Error (active) E0312 no suitable user-defined conversion from "lambda []()-><error-type>" to "const std::vector<int, std::allocator<int>>" exists consoleapplication C:Usersinsmitrsourcereposconsoleapplicationconsoleapplication.cpp 46 IntelliSense
2.Severity Code Description Project File Line Source Suppression State
Error (active) E0079 expected a type specifier consoleapplication C:Usersinsmitrsourcereposconsoleapplicationconsoleapplication.cpp 47 IntelliSense
你能在这方面帮助我吗
问题是print接受vector<int>，但在调用print时，您传递了一个lambda，并且由于没有从lambda到向量的隐式转换，因此您得到了上述错误。
您不一定需要调用print，因为您只需调用lambda本身，如下所示。另一种方法是使print成为一个函数模板，这样它可以接受任何可调用对象，然后调用传递的可调用对象。
int main()
{
std::vector<int> numbers;
int value = 0;
cout << "Pushing back...n";
while (value >= 0) {
cout << "Enter number: ";
cin >> value;
if (value >= 0)
numbers.push_back(value);
}
//-------------------vvvv------>void added here
( [numbers]() -> void
{
cout << "Vector content: { ";
for (const int& num : numbers)
cout << num << " ";
cout << "}nn";
//----vv---->note the brackets for calling
})();
return 0;
}