i have this file called main.cpp

#include <iostream>
#include <fstream>
#include <sstream>
#include "headers/lexer.hpp"

int main(int argc, char **argv)
{
    if (argc < 2)
    {
        std::cout << "Please provide a file";
        exit(1);
    }

    std::cout << "Reading from: " << argv[1] << std::endl;
    std::ifstream mainFile(argv[1]);
    std::stringstream buf;

    char t;

    while (mainFile.get(t))
        buf << t;

    std::string orgCode = buf.str();
    std::cout << "The code is:" << std::endl
              << orgCode;

    Lexer lexer(orgCode);

    std::cout << std::endl
              << "Reached the end of the program";
    return 0;
}

with this header file lexer.hpp in a “headers” directory

#ifdef __LEXER_H
#define __LEXER_H

#include <string>
class lexer
{
public:
    Lexer(std::string sourceCode)
    {
        source = sourceCode;
        cursor = 0;
        size = sourceCode.length();
        curr = sourceCode.at(cursor);
    }

private:
    std::string source;
    int cursor;
    int size;
    char curr;
};
#endif

this is the tasks.json file:

{
    "version": "2.0.0",
    "tasks": [
        {
            "type": "cppbuild",
            "label": "C/C++: g++.exe build active file",
            "command": "C:\msys64\mingw64\bin\g++.exe",
            "args": [
                "${workspaceFolder}/*.cpp",
                "-o",
                "${fileDirname}\${fileBasenameNoExtension}",
            ],
            "group": {
                "kind": "build",
                "isDefault": true
            },
            "detail": "compiler: C:\msys64\mingw64\bin\g++.exe"
        }
    ]
}

and this this the c_cpp_proporties.json file:

`{
    "configurations": [
        {
            "name": "Win32",
            "includePath": [
                "${workspaceFolder}/**"
            ],
            "defines": [
                "_DEBUG",
                "UNICODE",
                "_UNICODE"
            ],
            "compilerPath": "C:\msys64\mingw64\bin\gcc.exe",
            "cStandard": "c17",
            "cppStandard": "gnu++17",
            "intelliSenseMode": "windows-gcc-x64"
        }
    ],
    "version": 4
}`

the problem is that the line Lexer lexer(orgCode); give an error identifier "Lexer" is undefined I have searched a lot and did not find a solution.

i have tried messing with the tasks.json file and the c_cpp_proporties.json file, but no matter what i did it did not work, like i changed the path a couple of time, and in the includePath i also tried to include a couple of direct paths to the header file, added in the args more args and still did not work