Add errno to socket creation failed exception

src/socket.cpp

@@ -44,6 +44,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 	#include <windows.h>
 	#include <winsock2.h>
 	#include <ws2tcpip.h>
+	#define LAST_SOCKET_ERR() WSAGetLastError()
 	typedef SOCKET socket_t;
 	typedef int socklen_t;
 #else
@@ -54,6 +55,7 @@ typedef int socklen_t;
 	#include <netdb.h>
 	#include <unistd.h>
 	#include <arpa/inet.h>
+	#define LAST_SOCKET_ERR() (errno)
 	typedef int socket_t;
 #endif
 
@@ -339,7 +341,8 @@ bool UDPSocket::init(bool ipv6, bool noExceptions)
 		if (noExceptions) {
 			return false;
 		} else {
-			throw SocketException("Failed to create socket");
+			throw SocketException(std::string("Failed to create socket: error ")
+				+ itos(LAST_SOCKET_ERR()));
 		}
 	}
 

src/socket.h

@@ -45,7 +45,7 @@ extern bool socket_enable_debug_output;
 class SocketException : public BaseException
 {
 public:
-	SocketException(const char *s):
+	SocketException(const std::string &s):
 		BaseException(s)
 	{
 	}
@@ -54,7 +54,7 @@ public:
 class ResolveError : public BaseException
 {
 public:
-	ResolveError(const char *s):
+	ResolveError(const std::string &s):
 		BaseException(s)
 	{
 	}
@@ -63,7 +63,7 @@ public:
 class SendFailedException : public BaseException
 {
 public:
-	SendFailedException(const char *s):
+	SendFailedException(const std::string &s):
 		BaseException(s)
 	{
 	}