Merge topic 'tutorial_dependency_inversion'

8ddf32196c Tutorial: Refactor MathFunctions code

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !7789

5 files changed, 71 insertions, 30 deletions

diff --git a/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt b/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt
index f81b563..861014d 100644
--- a/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt
+++ b/Help/guide/tutorial/Step8/MathFunctions/CMakeLists.txt
@@ -1,36 +1,43 @@
-add_library(MathFunctions mysqrt.cxx)
+add_library(MathFunctions MathFunctions.cxx mysqrt.cxx)
+
+# should we use our own math functions
+option(USE_MYMATH "Use tutorial provided math implementation" ON)
+if (USE_MYMATH)
+  target_compile_definitions(MathFunctions PRIVATE "USE_MYMATH")
+
+  # does this system provide the log and exp functions?
+  include(CheckCXXSourceCompiles)
+  check_cxx_source_compiles("
+    #include <cmath>
+    int main() {
+      std::log(1.0);
+      return 0;
+    }
+  " HAVE_LOG)
+  check_cxx_source_compiles("
+    #include <cmath>
+    int main() {
+      std::exp(1.0);
+      return 0;
+    }
+  " HAVE_EXP)
+
+  # add compile definitions
+  if(HAVE_LOG AND HAVE_EXP)
+    target_compile_definitions(MathFunctions
+                               PRIVATE "HAVE_LOG" "HAVE_EXP"
+                               )
+  endif()
+endif()
 
 # state that anybody linking to us needs to include the current source dir
 # to find MathFunctions.h, while we don't.
 target_include_directories(MathFunctions
-          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
-          )
+                           INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
+                           )
 
 # link our compiler flags interface library
-target_link_libraries(MathFunctions tutorial_compiler_flags)
-
-# does this system provide the log and exp functions?
-include(CheckCXXSourceCompiles)
-check_cxx_source_compiles("
-  #include <cmath>
-  int main() {
-    std::log(1.0);
-    return 0;
-  }
-" HAVE_LOG)
-check_cxx_source_compiles("
-  #include <cmath>
-  int main() {
-    std::exp(1.0);
-    return 0;
-  }
-" HAVE_EXP)
-
-# add compile definitions
-if(HAVE_LOG AND HAVE_EXP)
-  target_compile_definitions(MathFunctions
-                             PRIVATE "HAVE_LOG" "HAVE_EXP")
-endif()
+target_link_libraries(MathFunctions PUBLIC tutorial_compiler_flags)
 
 # install libs
 set(installable_libs MathFunctions tutorial_compiler_flags)
diff --git a/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.cxx b/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.cxx
new file mode 100644
index 0000000..dc28b4b
--- /dev/null
+++ b/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.cxx
@@ -0,0 +1,19 @@
+#include "MathFunctions.h"
+
+#include <cmath>
+
+#ifdef USE_MYMATH
+#  include "mysqrt.h"
+#endif
+
+namespace mathfunctions {
+double sqrt(double x)
+{
+// which square root function should we use?
+#ifdef USE_MYMATH
+  return detail::mysqrt(x);
+#else
+  return std::sqrt(x);
+#endif
+}
+}
diff --git a/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.h b/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.h
index cd36bcc..d5c2f22 100644
--- a/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.h
+++ b/Help/guide/tutorial/Step8/MathFunctions/MathFunctions.h
@@ -1 +1,5 @@
-double mysqrt(double x);
+#pragma once
+
+namespace mathfunctions {
+double sqrt(double x);
+}
diff --git a/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx
index 7eecd26..28ab042 100644
--- a/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx
+++ b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx
@@ -1,8 +1,10 @@
+#include "mysqrt.h"
+
 #include <cmath>
 #include <iostream>
 
-#include "MathFunctions.h"
-
+namespace mathfunctions {
+namespace detail {
 // a hack square root calculation using simple operations
 double mysqrt(double x)
 {
@@ -30,3 +32,5 @@ double mysqrt(double x)
 #endif
   return result;
 }
+}
+}
diff --git a/Help/guide/tutorial/Step8/MathFunctions/mysqrt.h b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.h
new file mode 100644
index 0000000..593d41e
--- /dev/null
+++ b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace mathfunctions {
+namespace detail {
+double mysqrt(double x);
+}
+}