Ошибка е0304 c

Не понимаю, откуда эта ошибка появляется. Уже изучил, почему она может вызываться, но мне это никак не помогло в поиске/решении проблемы. Что надо сделать?
Код с реализацией функций:

#pragma once

#include <vector>
#include <iostream>
#include <random>

template <typename T>
void create_huge_matrix(std::vector<std::vector<T>>& matrix, T lowerLimit);
template <typename T>
void create_freeMatrixColumn(std::vector<T>& freeMatrixColumn);

template <typename T>
inline void create_huge_matrix(std::vector<std::vector<T>>& matrix, T lowerLimit)
{
	//std::vector<std::vector<T>> huge_matrix;
	std::random_device random_device; // Источник энтропии
	std::mt19937 generator(random_device()); // Генератор случайных чисел
	std::uniform_int_distribution<> distribution(lowerLimit, lowerLimit * 2);

	for (int i = 0; i < matrix[0].size(); i++)
	{
		for (int j = 0; j < matrix[0].size(); j++)
		{
			if (i == j) matrix[i][j] = distribution(generator);
			else matrix[i][j] = rand() % 2;
		}
	}
}

template <typename T>
inline void create_freeMatrixColumn(std::vector<T> &freeMatrixColumn)
{
	for (int i = 0; i < size; i++)
		freeMatrixColumn[i] = (rand() % 100) / 10;
}

Часть кода из функции main.cpp (где вызываю/есть ошибка):

#include <iostream>
#include <vector>
#include <cmath>
#include "gauss_serial.h"
#include "gauss_parallel.h"
#include "huge_matrix.h"

bool check_answer(std::vector<double> answer, std::vector<double> freeMatrixCloumn, std::vector<std::vector<double>> matrix);
void create_new_freeColumn(std::vector<double>& v, std::vector<double>& answer, std::vector<std::vector<double>> matrix);
void keep_4_digits_after_point(std::vector<double>& v);

int main()
{
    setlocale(LC_ALL, "utf-8");

    int m; // количество строк
    int n; // количество столбцов
    double value; // значение элемента массива
    std::vector<std::vector<double>> matrix_s, matrix_p, matrixForChecking; // матрица элементов без столбца свободных членов
    std::vector<double> freeMatrixColumn_s, freeMatrixColumn_p, freeMatrixColumnForChecking; // столбец свободных членов

    printf("Решение СЛАУ методом Гауссаn");
    // Задаём размерность матрицы
    printf("Укажите размерность матрицыn");
    printf("Количество строк: ");
    std::cin >> m;
    matrix_s.resize(m);
    matrix_p.resize(m);
    matrixForChecking.resize(m);
    printf("Количество столбцов: ");
    std::cin >> n;

    create_huge_matrix(matrix_s, 5);
    create_huge_matrix(matrix_p);
    create_huge_matrix(matrixForChecking);

DisplayMap.insert(i, map[i]);

As you can see in the above sample, I’ve tried to use the insert function, but it keeps displaying the same E0304 Error, which is for an overloaded function. In VS2019, the error details are:

Severity    Code    Description Project File    Line    Suppression State
Error (active)  E0304   no instance of overloaded function "std::basic_string<_Elem, _Traits, _Alloc>::insert [with _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char>]" matches the argument list

The error says that the arguments don’t match because the different overloads have different arguments.
Can you help me solve this error?
Here’s my full code if you need it:

#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <Windows.h>
#include <conio.h>
#include <algorithm>
#include <string>
#include "Data.h"
using namespace std;

int main() {
    SetConsoleDisplayMode(GetStdHandle(STD_OUTPUT_HANDLE), CONSOLE_FULLSCREEN_MODE, 0);
    CONSOLE_SCREEN_BUFFER_INFO csbi;
    int WindowColumns, WindowRows, DisplayBuffer;
    string DisplayMap;
    GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi);
    WindowColumns = csbi.srWindow.Right - csbi.srWindow.Left + 1;
    WindowRows = csbi.srWindow.Bottom - csbi.srWindow.Top + 1;
    cout << WindowColumns << "," << WindowRows;
    DisplayBuffer = WindowColumns * WindowRows;
    for (int i = 0; i < WindowColumns; i++) {
        DisplayMap.insert(i, map[i]);
    }
    return 0;
}

Thanks In advance.

EDIT:
Data.h here:

#pragma once

#include <iostream>
#include <String>
using namespace std;
string savedMap = "                              "
"                              "
"                              "
"                              "
"                              ";
string map = savedMap;
int w = 119, a = 97, s = 115, d = 100;
char key_press;
int myPOS = 35;
int MDPOS = myPOS, ascii_value;

Please don’t ask me why I use the namespace std in a header file.

DisplayMap.insert(i, map[i]);

As you can see in the above sample, I’ve tried to use the insert function, but it keeps displaying the same E0304 Error, which is for an overloaded function. In VS2019, the error details are:

Severity    Code    Description Project File    Line    Suppression State
Error (active)  E0304   no instance of overloaded function "std::basic_string<_Elem, _Traits, _Alloc>::insert [with _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char>]" matches the argument list

The error says that the arguments don’t match because the different overloads have different arguments.
Can you help me solve this error?
Here’s my full code if you need it:

#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <Windows.h>
#include <conio.h>
#include <algorithm>
#include <string>
#include "Data.h"
using namespace std;

int main() {
    SetConsoleDisplayMode(GetStdHandle(STD_OUTPUT_HANDLE), CONSOLE_FULLSCREEN_MODE, 0);
    CONSOLE_SCREEN_BUFFER_INFO csbi;
    int WindowColumns, WindowRows, DisplayBuffer;
    string DisplayMap;
    GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi);
    WindowColumns = csbi.srWindow.Right - csbi.srWindow.Left + 1;
    WindowRows = csbi.srWindow.Bottom - csbi.srWindow.Top + 1;
    cout << WindowColumns << "," << WindowRows;
    DisplayBuffer = WindowColumns * WindowRows;
    for (int i = 0; i < WindowColumns; i++) {
        DisplayMap.insert(i, map[i]);
    }
    return 0;
}

Thanks In advance.

EDIT:
Data.h here:

#pragma once

#include <iostream>
#include <String>
using namespace std;
string savedMap = "                              "
"                              "
"                              "
"                              "
"                              ";
string map = savedMap;
int w = 119, a = 97, s = 115, d = 100;
char key_press;
int myPOS = 35;
int MDPOS = myPOS, ascii_value;

Please don’t ask me why I use the namespace std in a header file.

Severity	Code	Source	        Description	
Error (active)	E0304	IntelliSense	no instance of function template "__countof_helper" matches the argument list	
 

Every single one of these calls (or at least every one I looked at) was calling
_countof like this snippet:

TCHAR ErrMsg[ERR_MSG_SIZE] = { (TCHAR)NULL };
...
FormatErrorString(GetLastError(), ErrMsg, _countof(ErrMsg), true);

This project is:

— Targeting Windows 10 as a platform

— 10.0.17134.0 as the Windows SDK Version

— has 64-bit config (UNICODE defined) and 32-bit config (UNICODE
not defined) profiles

— using «C++ 17 Standard» as the C++ Language Standard

DisplayMap.insert(i, map[i]);

As you can see in the above sample, I’ve tried to use the insert function, but it keeps displaying the same E0304 Error, which is for an overloaded function. In VS2019, the error details are:

Severity    Code    Description Project File    Line    Suppression State
Error (active)  E0304   no instance of overloaded function "std::basic_string<_Elem, _Traits, _Alloc>::insert [with _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char>]" matches the argument list

The error says that the arguments don’t match because the different overloads have different arguments.
Can you help me solve this error?
Here’s my full code if you need it:

#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <Windows.h>
#include <conio.h>
#include <algorithm>
#include <string>
#include "Data.h"
using namespace std;

int main() {
    SetConsoleDisplayMode(GetStdHandle(STD_OUTPUT_HANDLE), CONSOLE_FULLSCREEN_MODE, 0);
    CONSOLE_SCREEN_BUFFER_INFO csbi;
    int WindowColumns, WindowRows, DisplayBuffer;
    string DisplayMap;
    GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi);
    WindowColumns = csbi.srWindow.Right - csbi.srWindow.Left + 1;
    WindowRows = csbi.srWindow.Bottom - csbi.srWindow.Top + 1;
    cout << WindowColumns << "," << WindowRows;
    DisplayBuffer = WindowColumns * WindowRows;
    for (int i = 0; i < WindowColumns; i++) {
        DisplayMap.insert(i, map[i]);
    }
    return 0;
}

Thanks In advance.

EDIT:
Data.h here:

#pragma once

#include <iostream>
#include <String>
using namespace std;
string savedMap = "                              "
"                              "
"                              "
"                              "
"                              ";
string map = savedMap;
int w = 119, a = 97, s = 115, d = 100;
char key_press;
int myPOS = 35;
int MDPOS = myPOS, ascii_value;

Please don’t ask me why I use the namespace std in a header file.