Including mongoose.h in a Windows C++ project breaks other includes and has many conflicts with winsock

[ThomasR95]

Hi, I'm trying to add mongoose to an existing project.
Before I added mongoose, the project built without errors.
After including mongoose.h, I get many errors about redefinitions and missing declarations.

...etc.
I've followed the guide to the best of my ability. I started by simply including mongoose.h and mongoose.c in my Visual Studio project, but when this returned errors, I went to the internet for advice and found the idea of building mongoose as a separate library and linking to it, to hopefully avoid such conflicts. Unfortunately that didn't make any difference.
Here are my includes in main.cpp:

#include <string>
#include <iostream>
#include <random>
#include <deque>

#define IMGUI_DISABLE_WIN32_FUNCTIONS
#define IMGUI_ENABLE_FREETYPE
#include "imgui.h"
#include "imgui/misc/freetype/imgui_freetype.h"
#include "imgui-SFML.h"
#include "imgui_internal.h"

#include "defines.h"
#include <fstream>

#ifdef _WIN32
#include "spout2/SpoutSender.h"
#include "wtypes.h"
#include <Windows.h>
#include <fileapi.h>
#include <Dwmapi.h>
#include "CrashHandler.h"

#pragma comment (lib, "Dwmapi.lib")
#endif

#include "Config.h"
#include "xmlConfig.h"
#include "LayerManager.h"

// must be last?
#include "websocket.h"

and here is websocket.h:

#pragma once
#include <iostream>

#include "mongoose.h"

void ev_handler(struct mg_connection* c, int ev, void* ev_data)
{
if (ev == MG_EV_HTTP_MSG)
{
	struct mg_http_message* hm = (struct mg_http_message*)ev_data;

	std::cout << hm->message.buf << std::endl;
}
}

class WebSocket
{

public:
void Start()
{
	mg_mgr_init(&eventManager);
	mg_http_listen(&eventManager, "http://0.0.0.0:8000", ev_handler, NULL);
}

void Poll()
{
	mg_mgr_poll(&eventManager, 1000);
}

~WebSocket()
{
	mg_mgr_free(&eventManager);
}

private:

struct mg_mgr eventManager;

};

Please could somebody help me get this building? Thanks in advance!

[scaprile]

TL;DR
Please be kind to us and clearly explain which warnings/errors you have without forcing us to try to read from a snapshot. Please correctly paste the warning text, and please don't send long code, we are busy writing Mongoose code.
Also, try to see why Visual Studio does not like that, because we test with minGW++ every night

[scaprile]

There are over 100 errors,

Well, if you ever worked with C, you know that it is usually the first one you should see.

Mongoose is C, not C++, whatever you are doing when you include it triggers something that your compiler does not like.

[ThomasR95]

Clearly. What I'm hoping for is some insight on how including it might be upsetting the compiler. I've already sent what I'm doing to include it.

The first error is that std::map undefined issue. Doesn't tell me much, as std::map is defined when I don't include mongoose.

I'm aware that mongoose is C but your website says it works in C++, and doesn't provide any special instructions for integrating with C++. I've tried putting #include "mongoose.h" inside extern "C" but that didn't help.

[ThomasR95]

When I explicitly include again to get rid of that error (not sure why it appeared when it used to be working), the new first error is this:

1>C:\Program Files (x86)\Windows Kits\10\Include\10.0.22621.0\shared\ws2def.h(240,25): error C2011: 'sockaddr': 'struct' type redefinition
1>(compiling source file 'main.cpp')
1>    C:\Program Files (x86)\Windows Kits\10\Include\10.0.22621.0\um\winsock.h(482,8):
1>    see declaration of 'sockaddr'

I'm not including either ws2def or winsock myself, so I assume that's mongoose's doing, but I am including Windows.h for some other platform-specific things.

For anyone else who might run into this, here's the solution:

I found that adding #define WIN32_LEAN_AND_MEAN before my Windows.h inclusion was enough to get rid of the errors. I had to find other ways to include the bits I was then missing, but this was enough to get me past the issue.

[scaprile]

If you have a problem with includes in your environment, you have to track down your problem with your includes in your scenario. We have lots of examples that do work, and we build every day on VC for testing purposes, so unless you find there is a problem with our code, it is not.
If you read the docs, you'll see that Mongoose is told on which architecture (MG_ARCH) it is running, and it detects Linux, Mac and Windows.
If you see the code, you'll see that your magic words are already spoken by mongoose.h:

mongoose/src/arch_win32.h

Lines 9 to 10 in 6cf36b5

	#ifndef WIN32_LEAN_AND_MEAN
	#define WIN32_LEAN_AND_MEAN

so if that means anything to you, then your whatever needs that should either be after mongoose.h or you should know what you are including and why you are including it.
What mongoose includes is not an obscure set of hidden magic things, but this:

mongoose/src/arch_win32.h

Lines 3 to 134 in 6cf36b5

	#if MG_ARCH == MG_ARCH_WIN32
	#ifndef _CRT_RAND_S
	#define _CRT_RAND_S
	#endif
	#ifndef WIN32_LEAN_AND_MEAN
	#define WIN32_LEAN_AND_MEAN
	#endif
	#ifndef _CRT_SECURE_NO_WARNINGS
	#define _CRT_SECURE_NO_WARNINGS
	#endif
	#ifndef _WINSOCK_DEPRECATED_NO_WARNINGS
	#define _WINSOCK_DEPRECATED_NO_WARNINGS
	#endif
	#include <ctype.h>
	#include <direct.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <limits.h>
	#include <signal.h>
	#include <stdarg.h>
	#include <stddef.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <time.h>
	#if defined(_MSC_VER) && _MSC_VER < 1700
	#define __func__ ""
	typedef __int64 int64_t;
	typedef unsigned __int64 uint64_t;
	typedef unsigned char uint8_t;
	typedef char int8_t;
	typedef unsigned short uint16_t;
	typedef short int16_t;
	typedef unsigned int uint32_t;
	typedef int int32_t;
	typedef enum { false = 0, true = 1 } bool;
	#else
	#include <stdbool.h>
	#include <stdint.h>
	#include <ws2tcpip.h>
	#endif
	#include <process.h>
	#include <winerror.h>
	#include <winsock2.h>
	// For mg_random()
	#if defined(_MSC_VER) && _MSC_VER < 1700
	#ifndef _WIN32_WINNT
	#define _WIN32_WINNT 0x400 // Let vc98 pick up wincrypt.h
	#endif
	#include <wincrypt.h>
	#pragma comment(lib, "advapi32.lib")
	#endif
	// Protect from calls like std::snprintf in app code
	// See https://github.com/cesanta/mongoose/issues/1047
	#ifndef __cplusplus
	#define snprintf _snprintf
	#define vsnprintf _vsnprintf
	#ifndef strdup // For MSVC with _DEBUG, see #1359
	#define strdup(x) _strdup(x)
	#endif
	#endif
	#define MG_INVALID_SOCKET INVALID_SOCKET
	#define MG_SOCKET_TYPE SOCKET
	typedef unsigned long nfds_t;
	#if defined(_MSC_VER)
	#pragma comment(lib, "ws2_32.lib")
	#ifndef alloca
	#define alloca(a) _alloca(a)
	#endif
	#endif
	#define poll(a, b, c) WSAPoll((a), (b), (c))
	#define closesocket(x) closesocket(x)
	typedef int socklen_t;
	#define MG_DIRSEP '\\'
	#ifndef MG_PATH_MAX
	#define MG_PATH_MAX FILENAME_MAX
	#endif
	#ifndef SO_EXCLUSIVEADDRUSE
	#define SO_EXCLUSIVEADDRUSE ((int) (~SO_REUSEADDR))
	#endif
	#define MG_SOCK_ERR(errcode) ((errcode) < 0 ? WSAGetLastError() : 0)
	#define MG_SOCK_PENDING(errcode) \
	(((errcode) < 0) && \
	(WSAGetLastError() == WSAEINTR || WSAGetLastError() == WSAEINPROGRESS || \
	WSAGetLastError() == WSAEWOULDBLOCK))
	#define MG_SOCK_RESET(errcode) \
	(((errcode) < 0) && (WSAGetLastError() == WSAECONNRESET))
	#define realpath(a, b) _fullpath((b), (a), MG_PATH_MAX)
	#define sleep(x) Sleep((x) * 1000)
	#define mkdir(a, b) _mkdir(a)
	#define timegm(x) _mkgmtime(x)
	#ifndef S_ISDIR
	#define S_ISDIR(x) (((x) & _S_IFMT) == _S_IFDIR)
	#endif
	#ifndef MG_ENABLE_DIRLIST
	#define MG_ENABLE_DIRLIST 1
	#endif
	#ifndef SIGPIPE
	#define SIGPIPE 0
	#endif
	#ifndef MG_ENABLE_POSIX_FS
	#define MG_ENABLE_POSIX_FS 1
	#endif
	#ifndef MG_IO_SIZE
	#define MG_IO_SIZE 16384
	#endif
	#endif

you don't have to assume, but look at the source code