add support for gcc and clang 7

Uses std::experimental::filesystem

Signed-off-by: Rosen Penev <rosenp@gmail.com>

app/actions.cpp

@@ -17,16 +17,15 @@
 #include "types.hpp"
 #include "xmp_exiv2.hpp"
 
-// + standard includes
-#include <sys/stat.h>   // for stat()
-#include <sys/types.h>  // for stat()
-
-#include <filesystem>
 #include <fstream>
 #include <iomanip>
 #include <iostream>
 #include <mutex>
 #include <sstream>
+
+// + standard includes
+#include <sys/stat.h>   // for stat()
+#include <sys/types.h>  // for stat()
 #ifdef EXV_HAVE_UNISTD_H
 #include <unistd.h>  // for stat()
 #endif
@@ -46,7 +45,13 @@
   } while (false)
 #endif
 
+#if __has_include(<filesystem>)
+#include <filesystem>
 namespace fs = std::filesystem;
+#else
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#endif
 
 // *****************************************************************************
 // local declarations

app/getopt.cpp

@@ -5,9 +5,14 @@
 
 #include <cstdio>
 #include <cstring>
-#include <filesystem>
 
+#if __has_include(<filesystem>)
+#include <filesystem>
 namespace fs = std::filesystem;
+#else
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#endif
 
 namespace Util {
 // https://raw.githubusercontent.com/skeeto/getopt/master/getopt.h

samples/path-test.cpp

@@ -2,11 +2,16 @@
 
 #include <exiv2/exiv2.hpp>
 
-#include <filesystem>
 #include <fstream>
 #include <iostream>
 
+#if __has_include(<filesystem>)
+#include <filesystem>
 namespace fs = std::filesystem;
+#else
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#endif
 
 int main(int argc, char* const argv[]) {
   Exiv2::XmpParser::initialize();

src/basicio.cpp

@@ -19,7 +19,6 @@
 #include <cstdlib>  // for alloc, realloc, free
 #include <cstring>  // std::memcpy
 #include <ctime>    // timestamp for the name of temporary file
-#include <filesystem>
 #include <fstream>  // write the temporary file
 #include <iostream>
 
@@ -43,7 +42,13 @@
 #include <windows.h>
 #endif
 
+#if __has_include(<filesystem>)
+#include <filesystem>
 namespace fs = std::filesystem;
+#else
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#endif
 
 // *****************************************************************************
 // class member definitions

src/futils.cpp

@@ -12,15 +12,16 @@
 #include <algorithm>
 #include <array>
 #include <cstring>
-#include <filesystem>
 #include <sstream>
 #include <stdexcept>
 
-#ifdef EXV_HAVE_UNISTD_H
-#include <unistd.h>  // for stat()
-#endif
-
+#if __has_include(<filesystem>)
+#include <filesystem>
 namespace fs = std::filesystem;
+#else
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#endif
 
 #if defined(_WIN32)
 // clang-format off
@@ -42,7 +43,10 @@ namespace fs = std::filesystem;
 #include <sys/sysctl.h>
 #include <sys/types.h>
 #include <sys/un.h>
-#include <unistd.h>
+#endif
+
+#ifdef EXV_HAVE_UNISTD_H
+#include <unistd.h>  // for stat()
 #endif
 
 #ifndef _MAX_PATH
@@ -374,7 +378,7 @@ std::string getProcessPath() {
     ret = path;
   }
 #elif defined(__unix__)
-  ret = std::filesystem::read_symlink("/proc/self/exe");
+  ret = fs::read_symlink("/proc/self/exe");
 #endif
 
   const size_t idxLastSeparator = ret.find_last_of(EXV_SEPARATOR_CHR);

src/makernote_int.cpp

@@ -15,14 +15,16 @@
 #include "utils.hpp"
 
 // + standard includes
-#ifdef EXV_ENABLE_INIH
-#include <INIReader.h>
-#endif
 #include <array>
-#include <filesystem>
 #include <iostream>
 
+#if __has_include(<filesystem>)
+#include <filesystem>
 namespace fs = std::filesystem;
+#else
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#endif
 
 #if !defined(_WIN32)
 #include <pwd.h>
@@ -33,7 +35,10 @@ namespace fs = std::filesystem;
 #define CSIDL_PROFILE 40
 #endif
 #include <process.h>
+#endif
 
+#ifdef EXV_ENABLE_INIH
+#include <INIReader.h>
 #endif
 
 // *****************************************************************************

unitTests/test_ImageFactory.cpp

@@ -5,10 +5,16 @@
 #include <error.hpp>  // Need to include this header for the Exiv2::Error exception
 
 #include <gtest/gtest.h>
+
+#if __has_include(<filesystem>)
 #include <filesystem>
+namespace fs = std::filesystem;
+#else
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#endif
 
 using namespace Exiv2;
-namespace fs = std::filesystem;
 
 TEST(TheImageFactory, createsInstancesForFewSupportedTypesInMemory) {
   // Note that the constructor of these Image classes take an 'create' argument

unitTests/test_futils.cpp

@@ -7,13 +7,18 @@
 // Auxiliary headers
 #include <cerrno>
 #include <cstdio>
-#include <filesystem>
 #include <fstream>
 #include <stdexcept>
 
 #include <gtest/gtest.h>
 
+#if __has_include(<filesystem>)
+#include <filesystem>
 namespace fs = std::filesystem;
+#else
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#endif
 
 using namespace Exiv2;