c++ - 类型不完整错误(E0409，E0070，E0515)

Question

在我的代码Main.cpp中，下面显示了以下内容。我遇到的问题是tuple<int, int, int>我不断收到这三个错误
function "sPA" returns incomplete type "trie"，incomplete type is not allowed和cannot convert to incomplete class "trie"
我在这里做错了什么才能导致此错误？

 // Main.cpp
 #include <iostream>
 #include <string>
 using namespace std;

 typedef pair<int, int> int_pair;
 typedef tuple<int, int, int> trie;



 int_pair sum_and_product(int a, int b) {
     return int_pair(a + b, a * b);
 }

 trie sPA(int a, int b, int c) {
     trie t{ a + b + c,a * b * c,((a + b + c) / 3) };
     return t;
 } 

 void consuming_templates() {
     int a = 2, b = 3, c = 4;
     auto results = sum_and_product(a,b);
     cout << "sum = " << results.first << "|product = " << results.second << endl;
     auto r2 = sPA(a, b, c);
 }

int main(int argc, char* argv[]) {

    consuming_templates();

    return 0;
}

Answer 1

idclev 463035818和M.M发表了评论以回答我的问题

您需要做#include <tuple>和#include <utility>