https://github.com/Exiv2/exiv2/issues/555

I have restored the Macro EXIV2_TEST_VERSION in include/exiv2/version.hpp
I have added an option --version-test to exifprint.cpp to test/validate EXIV2_TEST_VERSION works as documented.
Version strings in Exiv2 v0.27 and later have a fourth digit to indicate the pre-release number of the build.
Pre-release builds should never be used for production purposes.

include/exiv2/version.hpp

@@ -80,6 +80,52 @@
 #define EXIV2_VERSION \
     EXIV2_MAKE_VERSION(EXIV2_MAJOR_VERSION,EXIV2_MINOR_VERSION,EXIV2_PATCH_VERSION)
 
+/*!
+  @brief Macro to test the version the %Exiv2 library at compile-time.
+         Return true if it is the same as or newer than the passed-in version.
+
+  Versions prior to v0.27 are denoted using a triplet of integers: \em MAJOR.MINOR.PATCH .
+  From v0.27 forward, the fourth digit is a "tweak" and designates the pre-release number of the version.
+
+  @code
+  // Application code is expected to include <exiv2/exiv2.hpp>
+  // Don't include the <exiv2/version.hpp> file directly
+  // Early Exiv2 versions didn't have version.hpp and the macros.
+
+  #include <exiv2/exiv2.hpp>
+
+  // Make sure an EXIV2_TEST_VERSION macro exists:
+  #ifdef EXIV2_VERSION
+  # ifndef EXIV2_TEST_VERSION
+  # define EXIV2_TEST_VERSION(major,minor,patch) \
+      ( EXIV2_VERSION >= EXIV2_MAKE_VERSION(major,minor,patch) )
+  # endif
+  #else
+  # define EXIV2_TEST_VERSION(major,minor,patch) (false)
+  #endif
+
+  std::cout << "Compiled with Exiv2 version " << EXV_PACKAGE_VERSION << "\n"
+            << "Runtime Exiv2 version is    " << Exiv2::version()    << "\n";
+
+  // Test the Exiv2 version available at runtime but compile the if-clause only if
+  // the compile-time version is at least 0.15. Earlier versions didn't have a
+  // testVersion() function:
+
+  #if EXIV2_TEST_VERSION(0,15,0)
+  if (Exiv2::testVersion(0,13,0)) {
+      std::cout << "Available Exiv2 version is equal to or greater than 0.13\n";
+  }
+  else {
+      std::cout << "Installed Exiv2 version is less than 0.13\n";
+  }
+  #else
+  std::cout << "Compile-time Exiv2 version doesn't have Exiv2::testVersion()\n";
+  #endif
+  @endcode
+ */
+#define EXIV2_TEST_VERSION(major,minor,patch) \
+    ( EXIV2_VERSION >= EXIV2_MAKE_VERSION(major,minor,patch) )
+
 // *****************************************************************************
 // namespace extensions
 namespace Exiv2 {
@@ -96,6 +142,19 @@ namespace Exiv2 {
     */
     EXIV2API std::string versionNumberHexString();
 
+    /*!
+      @brief Return the version of %Exiv2 as "C" string eg "0.27.0.2".
+    */
+    EXIV2API const char* version();
+
+    /*!
+      @brief Test the version of the available %Exiv2 library at runtime. Return
+             true if it is the same as or newer than the passed-in version.
+
+      Versions are denoted using a triplet of integers: \em major.minor.patch .
+      The fourth version number is designated a "tweak" an used by Release Candidates
+    */
+    EXIV2API bool testVersion(int major, int minor, int patch);
     /*!
       @brief dumpLibraryInfo implements the exiv2 option --version --verbose
              used by exiv2 test suite to inspect libraries loaded at run-time

samples/exifprint.cpp

@@ -33,14 +33,38 @@ try {
     const _tchar* file = argv[1];
 
     if (argc != 2) {
-        std::_tcout << _t("Usage: ") << prog << _t(" [ file | --version ]") << std::endl;
+        std::_tcout << _t("Usage: ") << prog << _t(" [ file | --version || --version-test ]") << std::endl;
         return 1;
     }
 
     if ( _tstrcmp(file,_t("--version")) == 0 ) {
-    	exv_grep_keys_t keys;
-    	Exiv2::dumpLibraryInfo(std::cout,keys);
-    	return 0;
+        exv_grep_keys_t keys;
+        Exiv2::dumpLibraryInfo(std::cout,keys);
+        return 0;
+    } else if ( _tstrcmp(file,_t("--version-test")) == 0 ) {
+        // verifies/test macro EXIV2_TEST_VERSION
+        // described in include/exiv2/version.hpp
+        std::cout << "EXV_PACKAGE_VERSION             " << EXV_PACKAGE_VERSION             << std::endl
+                  << "Exiv2::version()                " << Exiv2::version()                << std::endl
+                  << "strlen(Exiv2::version())        " << ::strlen(Exiv2::version())      << std::endl
+                  << "Exiv2::versionNumber()          " << Exiv2::versionNumber()          << std::endl
+                  << "Exiv2::versionString()          " << Exiv2::versionString()          << std::endl
+                  << "Exiv2::versionNumberHexString() " << Exiv2::versionNumberHexString() << std::endl
+                  ;
+
+        // Test the Exiv2 version available at runtime but compile the if-clause only if
+        // the compile-time version is at least 0.15. Earlier versions didn't have a
+        // testVersion() function:
+        #if EXIV2_TEST_VERSION(0,15,0)
+            if (Exiv2::testVersion(0,13,0)) {
+              std::cout << "Available Exiv2 version is equal to or greater than 0.13\n";
+            } else {
+              std::cout << "Installed Exiv2 version is less than 0.13\n";
+            }
+        #else
+              std::cout << "Compile-time Exiv2 version doesn't have Exiv2::testVersion()\n";
+        #endif
+        return 0;
     }
 
     Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(file);

src/version.cpp

@@ -82,6 +82,17 @@ namespace Exiv2 {
         os << std::hex << std::setw(6) << std::setfill('0') << Exiv2::versionNumber();
         return os.str();
     }
+
+    const char* version()
+    {
+        return EXV_PACKAGE_VERSION;
+    }
+
+    bool testVersion(int major, int minor, int patch)
+    {
+        return versionNumber() >= EXIV2_MAKE_VERSION(major,minor,patch);
+    }
+
 }                                       // namespace Exiv2
 
 #ifndef lengthof