'HTTPREQ' in namespace 'std' does not name a type

I don't know much but for project I'm working on cpp code need help on this there are two files one is headerfile HTTPClient.h and other HTTPClient.cpp HTTPClient.h

#ifndef HTTPClient_H_
#define HTTPClient_H_
#define HTTPCLIENT_1_1_COMPATIBLE
#include <memory>
#include <Arduino.h>
#include <WiFiClient.h>
#include <WiFiClientSecure.h>
#define HTTPCLIENT_DEFAULT_TCP_TIMEOUT (5000)
using namespace std;
#define HTTPC_ERROR_CONNECTION_REFUSED  (-1)
#define HTTPC_ERROR_SEND_HEADER_FAILED  (-2)
#define HTTPC_ERROR_SEND_PAYLOAD_FAILED (-3)
#define HTTPC_ERROR_NOT_CONNECTED       (-4)
#define HTTPC_ERROR_CONNECTION_LOST     (-5)
#define HTTPC_ERROR_NO_STREAM           (-6)
#define HTTPC_ERROR_NO_HTTP_SERVER      (-7)
#define HTTPC_ERROR_TOO_LESS_RAM        (-8)
#define HTTPC_ERROR_ENCODING            (-9)
#define HTTPC_ERROR_STREAM_WRITE        (-10)
#define HTTPC_ERROR_READ_TIMEOUT        (-11)
#define HTTP_TCP_BUFFER_SIZE (1460)
typedef enum {
    HTTP_CODE_CONTINUE = 100,
    HTTP_CODE_SWITCHING_PROTOCOLS = 101,
    HTTP_CODE_PROCESSING = 102,
    HTTP_CODE_OK = 200,
    HTTP_CODE_CREATED = 201,
    HTTP_CODE_ACCEPTED = 202,
    HTTP_CODE_NON_AUTHORITATIVE_INFORMATION = 203,
    HTTP_CODE_NO_CONTENT = 204,
    HTTP_CODE_RESET_CONTENT = 205,
    HTTP_CODE_PARTIAL_CONTENT = 206,
    HTTP_CODE_MULTI_STATUS = 207,
    HTTP_CODE_ALREADY_REPORTED = 208,
    HTTP_CODE_IM_USED = 226,
    HTTP_CODE_MULTIPLE_CHOICES = 300,
    HTTP_CODE_MOVED_PERMANENTLY = 301,
    HTTP_CODE_FOUND = 302,
    HTTP_CODE_SEE_OTHER = 303,
    HTTP_CODE_NOT_MODIFIED = 304,
    HTTP_CODE_USE_PROXY = 305,
    HTTP_CODE_TEMPORARY_REDIRECT = 307,
    HTTP_CODE_PERMANENT_REDIRECT = 308,
    HTTP_CODE_BAD_REQUEST = 400,
    HTTP_CODE_UNAUTHORIZED = 401,
    HTTP_CODE_PAYMENT_REQUIRED = 402,
    HTTP_CODE_FORBIDDEN = 403,
    HTTP_CODE_NOT_FOUND = 404,
    HTTP_CODE_METHOD_NOT_ALLOWED = 405,
    HTTP_CODE_NOT_ACCEPTABLE = 406,
    HTTP_CODE_PROXY_AUTHENTICATION_REQUIRED = 407,
    HTTP_CODE_REQUEST_TIMEOUT = 408,
    HTTP_CODE_CONFLICT = 409,
    HTTP_CODE_GONE = 410,
    HTTP_CODE_LENGTH_REQUIRED = 411,
    HTTP_CODE_PRECONDITION_FAILED = 412,
    HTTP_CODE_PAYLOAD_TOO_LARGE = 413,
    HTTP_CODE_URI_TOO_LONG = 414,
    HTTP_CODE_UNSUPPORTED_MEDIA_TYPE = 415,
    HTTP_CODE_RANGE_NOT_SATISFIABLE = 416,
    HTTP_CODE_EXPECTATION_FAILED = 417,
    HTTP_CODE_MISDIRECTED_REQUEST = 421,
    HTTP_CODE_UNPROCESSABLE_ENTITY = 422,
    HTTP_CODE_LOCKED = 423,
    HTTP_CODE_FAILED_DEPENDENCY = 424,
    HTTP_CODE_UPGRADE_REQUIRED = 426,
    HTTP_CODE_PRECONDITION_REQUIRED = 428,
    HTTP_CODE_TOO_MANY_REQUESTS = 429,
    HTTP_CODE_REQUEST_HEADER_FIELDS_TOO_LARGE = 431,
    HTTP_CODE_INTERNAL_SERVER_ERROR = 500,
    HTTP_CODE_NOT_IMPLEMENTED = 501,
    HTTP_CODE_BAD_GATEWAY = 502,
    HTTP_CODE_SERVICE_UNAVAILABLE = 503,
    HTTP_CODE_GATEWAY_TIMEOUT = 504,
    HTTP_CODE_HTTP_VERSION_NOT_SUPPORTED = 505,
    HTTP_CODE_VARIANT_ALSO_NEGOTIATES = 506,
    HTTP_CODE_INSUFFICIENT_STORAGE = 507,
    HTTP_CODE_LOOP_DETECTED = 508,
    HTTP_CODE_NOT_EXTENDED = 510,
    HTTP_CODE_NETWORK_AUTHENTICATION_REQUIRED = 511
} t_http_codes;
typedef enum {
    HTTPC_TE_IDENTITY,
    HTTPC_TE_CHUNKED
} transferEncoding_t;
typedef enum {
    HTTPC_DISABLE_FOLLOW_REDIRECTS,
    HTTPC_STRICT_FOLLOW_REDIRECTS,
    HTTPC_FORCE_FOLLOW_REDIRECTS
} followRedirects_t;
#ifdef HTTPCLIENT_1_1_COMPATIBLE
class TransportTraits;
typedef std::unique_ptr<TransportTraits> TransportTraitsPtr;
#endif
namespace HTTPREQ{
class HTTPClient
{
public:
    HTTPClient();
    ~HTTPClient();
    bool begin(WiFiClient &client, String url);
    bool begin(WiFiClient &client, String host, uint16_t port, String uri = "/", bool https = false);
#ifdef HTTPCLIENT_1_1_COMPATIBLE
    bool begin(String url);
    bool begin(String url, const char* CAcert);
    bool begin(String host, uint16_t port, String uri = "/");
    bool begin(String host, uint16_t port, String uri, const char* CAcert);
    bool begin(String host, uint16_t port, String uri, const char* CAcert, const char* cli_cert, const char* cli_key);
#endif
    void end(void);
    bool connected(void);
    void setReuse(bool reuse);
    void setUserAgent(const String& userAgent);
    void setAuthorization(const char * user, const char * password);
    void setAuthorization(const char * auth);
    void setAuthorizationType(const char * authType);
    void setConnectTimeout(int32_t connectTimeout);
    void setTimeout(uint16_t timeout);
    void setFollowRedirects(followRedirects_t follow);
    void setRedirectLimit(uint16_t limit);
    bool setURL(const String &url);
    void useHTTP10(bool usehttp10 = true);
    int GET();
    int PATCH(uint8_t * payload, size_t size);
    int PATCH(String payload);
    int POST(uint8_t * payload, size_t size);
    int POST(String payload);
    int PUT(uint8_t * payload, size_t size);
    int PUT(String payload);
    int sendRequest(const char * type, String payload);
    int sendRequest(const char * type, uint8_t * payload = NULL, size_t size = 0);
    int sendRequest(const char * type, Stream * stream, size_t size = 0);
    void addHeader(const String& name, const String& value, bool first = false, bool replace = true);
    void collectHeaders(const char* headerKeys[], const size_t headerKeysCount);
    String header(const char* name);
    String header(size_t i);
    String headerName(size_t i);
    int headers();
    bool hasHeader(const char* name);
    int getSize(void);
    const String &getLocation(void);
    WiFiClient& getStream(void);
    WiFiClient* getStreamPtr(void);
    int writeToStream(Stream* stream);
    String getString(void);
    static String errorToString(int error);
protected:
    struct RequestArgument {
        String key;
        String value;
    };
    bool beginInternal(String url, const char* expectedProtocol);
    void disconnect(bool preserveClient = false);
    void clear();
    int returnError(int error);
    bool connect(void);
    bool sendHeader(const char * type);
    int handleHeaderResponse();
    int writeToStreamDataBlock(Stream * stream, int len);
#ifdef HTTPCLIENT_1_1_COMPATIBLE
    TransportTraitsPtr _transportTraits;
    std::unique_ptr<WiFiClient> _tcpDeprecated;
#endif
    WiFiClient* _client = nullptr;
    String _host;
    uint16_t _port = 0;
    int32_t _connectTimeout = -1;
    bool _reuse = true;
    uint16_t _tcpTimeout = HTTPCLIENT_DEFAULT_TCP_TIMEOUT;
    bool _useHTTP10 = false;
    bool _secure = false;
    String _uri;
    String _protocol;
    String _headers;
    String _userAgent = "ESP32HTTPClient";
    String _base64Authorization;
    String _authorizationType = "Basic";
    RequestArgument* _currentHeaders = nullptr;
    size_t           _headerKeysCount = 0;
    int _returnCode = 0;
    int _size = -1;
    bool _canReuse = false;
    followRedirects_t _followRedirects = HTTPC_DISABLE_FOLLOW_REDIRECTS;
    uint16_t _redirectLimit = 10;
    String _location;
    transferEncoding_t _transferEncoding = HTTPC_TE_IDENTITY;
};
}
#endif /* HTTPClient_H_ */

and the errors

HTTPClient.cpp:97:7: error: 'HTTPREQ' in namespace 'std' does not name a type
  std::HTTPREQ::HTTPREQ()
       ^
HTTPClient.cpp:104:14: error: scope 'HTTPREQ' before '~' is not a class-name
 int HTTPREQ::~HTTPREQ()
              ^

Error 1

main.cpp: In function 'void loop()':
main.cpp:670:16: error: expected primary-expression before 'http'
       HTTPREQ  http;
                ^
main.cpp:671:8: error: 'http' was not declared in this scope
        http.begin("http://xx.xx.xx:xxxx/");

Actually there's issue with HTTPClient because there's another HTTPClient cpp file and there's conflict class name(HTTPClient) so I tried namespace but I can't able to do that please help me in achieving this thanks in-advance......