passing by reference... my darkest enemy
actual reason below:
In your case (without reference) the compiler generates a temporary object (int) for the first argument of your MyApplication constructor. You pass this temporary int to QApplication’s constructor (with int reference), which saves the address of this reference. Once your MyApplication constructor is done the temporary int is destroyed but QApplication still has its address.
### Hedgewars
# - Try to find the Sparkle framework
# Once done this will define
#
# SPARKLE_FOUND - system has Sparkle
# SPARKLE_INCLUDE_DIR - the Sparkle include directory
# SPARKLE_LIBRARY - The library needed to use Sparkle
# Copyright (c) 2009, Vittorio Giovara, <vittorio.giovara@gmail.com>
#
# Redistribution and use is allowed according to the terms of a Creative Commons license.
# For details see http://creativecommons.org/licenses/by-sa/3.0/
# original version of this module was derived from Richard Laerkaeng, <richard@goteborg.utfors.se>
include (CheckLibraryExists)
find_path(SPARKLE_INCLUDE_DIR Sparkle.h)
find_library(SPARKLE_LIBRARY NAMES Sparkle)
if (SPARKLE_INCLUDE_DIR AND SPARKLE_LIBRARY)
set(SPARKLE_FOUND TRUE)
else ()
set(SPARKLE_FOUND FALSE)
endif ()
if (SPARKLE_FOUND)
if (NOT Sparkle_FIND_QUIETLY)
message(STATUS "Found Sparkle: ${SPARKLE_LIBRARY}")
endif ()
else ()
if (Sparkle_FIND_REQUIRED)
message(FATAL_ERROR "Could NOT find Sparkle framework")
else ()
if (NOT Sparkle_FIND_QUIETLY)
message(STATUS "Could NOT find Sparkle framework, autoupdate feature will be disabled")
endif()
endif ()
endif ()