wxWidgets/build/cmake/modules/FindIconv.cmake

# https://github.com/onyx-intl/cmake_modules/blob/master/FindIconv.cmake
#
# - Try to find Iconv
# Once done this will define
#
#  ICONV_FOUND - system has Iconv
#  ICONV_INCLUDE_DIR - the Iconv include directory
#  ICONV_LIBRARIES - Link these to use Iconv
#  ICONV_SECOND_ARGUMENT_IS_CONST - the second argument for iconv() is const
#
include(CheckCXXSourceCompiles)

IF (ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)
  # Already in cache, be silent
  SET(ICONV_FIND_QUIETLY TRUE)
ENDIF (ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)

FIND_PATH(ICONV_INCLUDE_DIR iconv.h)

FIND_LIBRARY(ICONV_LIBRARIES NAMES iconv libiconv libiconv-2 c)

IF(ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)
   SET(ICONV_FOUND TRUE)
ENDIF(ICONV_INCLUDE_DIR AND ICONV_LIBRARIES)

set(CMAKE_REQUIRED_INCLUDES ${ICONV_INCLUDE_DIR})
set(CMAKE_REQUIRED_LIBRARIES ${ICONV_LIBRARIES})
IF(ICONV_FOUND)
  check_cxx_source_compiles("
  #include <iconv.h>
  int main(){
    iconv_t conv = 0;
    const char* in = 0;
    size_t ilen = 0;
    char* out = 0;
    size_t olen = 0;
    iconv(conv, &in, &ilen, &out, &olen);
    return 0;
  }
" ICONV_SECOND_ARGUMENT_IS_CONST )
ENDIF(ICONV_FOUND)
set(CMAKE_REQUIRED_INCLUDES)
set(CMAKE_REQUIRED_LIBRARIES)

IF(ICONV_FOUND)
  IF(NOT ICONV_FIND_QUIETLY)
    MESSAGE(STATUS "Found Iconv: ${ICONV_LIBRARIES}")
  ENDIF(NOT ICONV_FIND_QUIETLY)
ELSE(ICONV_FOUND)
  IF(Iconv_FIND_REQUIRED)
    MESSAGE(FATAL_ERROR "Could not find Iconv")
  ENDIF(Iconv_FIND_REQUIRED)
ENDIF(ICONV_FOUND)

MARK_AS_ADVANCED(
  ICONV_INCLUDE_DIR
  ICONV_LIBRARIES
  ICONV_SECOND_ARGUMENT_IS_CONST
)