From 1a8b227c502454fb05cd619e208ff460304b9c33 Mon Sep 17 00:00:00 2001
From: Darius Neatu <dariusn@adobe.com>
Date: Wed, 12 Jun 2024 11:41:14 +0300
Subject: [PATCH] move/add examples to /examples

---
 CMakeLists.txt                                |  1 +
 examples/CMakeLists.txt                       | 32 ++++++++++++++
 examples/README.md                            | 42 +++++++++++++++++++
 .../optional_ref.cpp                          |  0
 examples/range_loop.cpp                       | 17 ++++++++
 examples/sample.cpp                           | 16 +++++++
 src/CMakeLists.txt                            |  1 -
 src/examples/CMakeLists.txt                   | 29 -------------
 src/examples/main.cpp                         |  4 --
 9 files changed, 108 insertions(+), 34 deletions(-)
 create mode 100644 examples/CMakeLists.txt
 create mode 100644 examples/README.md
 rename src/examples/before_after.cpp => examples/optional_ref.cpp (100%)
 create mode 100644 examples/range_loop.cpp
 create mode 100644 examples/sample.cpp
 delete mode 100644 src/examples/CMakeLists.txt
 delete mode 100644 src/examples/main.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 452671fd..ebc7bc12 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,6 +8,7 @@ set(TARGETS_EXPORT_NAME ${CMAKE_PROJECT_NAME}Targets)
 
 add_subdirectory(extern)
 add_subdirectory(src)
+add_subdirectory(examples)
 
 include(GNUInstallDirs)
 
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
new file mode 100644
index 00000000..fac02b85
--- /dev/null
+++ b/examples/CMakeLists.txt
@@ -0,0 +1,32 @@
+SET(BEMAN_OPTIONAL26_LIBRARY "beman_optional26")
+
+include(GNUInstallDirs)
+
+# List of all buildable examples.
+set(EXAMPLES
+  sample
+  range_loop
+  optional_ref
+)
+
+foreach(EXAMPLE ${EXAMPLES})
+  # Add example executable.
+  add_executable(${EXAMPLE} "")
+
+  # Add example source file.
+  target_sources(
+    ${EXAMPLE}
+    PRIVATE
+    ${EXAMPLE}.cpp
+  )
+
+  # Link example with the library.
+  target_link_libraries(${EXAMPLE} "${BEMAN_OPTIONAL26_LIBRARY}")
+
+  # Install .
+  install(
+    TARGETS ${EXAMPLE}
+    EXPORT ${TARGETS_EXPORT_NAME}
+    DESTINATION ${CMAKE_INSTALL_BINDIR}
+  )
+endforeach()
diff --git a/examples/README.md b/examples/README.md
new file mode 100644
index 00000000..b43db0be
--- /dev/null
+++ b/examples/README.md
@@ -0,0 +1,42 @@
+# Beman.Optional26 Examples
+
+List of usage examples for `Beman.Optional26`.
+
+## Sample
+
+Check [sample](sample.cpp) for basic `Beman.Optional26` library usage.
+
+Build and run instructions:
+```shell
+# build
+$ cmake --workflow --preset gcc-14
+
+# run sample
+$ .build/gcc-14/examples/RelWithDebInfo/sample
+empty_opt is empty!
+opt = 26
+```
+
+## Range Support (P3168R1)
+
+Range support added in [*Give std::optional Range Support* (P3168R1)](https://wg21.link/P3168R1) examples:
+* [./range_loop.cpp](./range_loop.cpp)
+
+
+Build and run instructions:
+
+```shell
+# build
+$ cmake --workflow --preset gcc-14
+
+# run range_loop
+$ .build/gcc-14/examples/RelWithDebInfo/range_loop
+                                               # note: 1st log (empty_opt) is missing from console!
+"for each loop" over C++26 optional: opt = 26  # 2nd log (non empty opt)
+```
+
+## Optional Reference (P2988R5)
+
+Reference support added in [*std::optional<T&>*(P2988R5)](https://wg21.link/P2988R5) examples:
+
+* [./optional_ref.cpp](./optional_ref.cpp)
diff --git a/src/examples/before_after.cpp b/examples/optional_ref.cpp
similarity index 100%
rename from src/examples/before_after.cpp
rename to examples/optional_ref.cpp
diff --git a/examples/range_loop.cpp b/examples/range_loop.cpp
new file mode 100644
index 00000000..dd29d055
--- /dev/null
+++ b/examples/range_loop.cpp
@@ -0,0 +1,17 @@
+#include <Beman/Optional26/optional.hpp>
+#include <iostream>
+
+int main() {
+    beman::optional::optional<int> empty_opt{};
+    for ([[maybe_unused]] const auto& i : empty_opt) {
+        // Should not see this in console.
+        std::cout << "\"for each loop\" over C++26 optional: empty_opt\n";
+    } 
+
+    beman::optional::optional<int> opt{26};
+    for (const auto& i : opt) {
+        // Should see this in console.
+        std::cout << "\"for each loop\" over C++26 optional: opt = " << i << "\n";
+    }    
+    return 0;
+}
diff --git a/examples/sample.cpp b/examples/sample.cpp
new file mode 100644
index 00000000..508eb049
--- /dev/null
+++ b/examples/sample.cpp
@@ -0,0 +1,16 @@
+#include <Beman/Optional26/optional.hpp>
+#include <print>
+
+int main() {
+    beman::optional::optional<int> empty_opt{};
+    if (!empty_opt) {
+        std::println("empty_opt is empty!");
+    }
+
+    beman::optional::optional<int> opt{26};
+    if (opt) {
+        std::println("opt = {}", *opt);
+    }
+
+    return 0;
+}
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 7b654f63..066cc47b 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,2 +1 @@
 add_subdirectory(beman)
-add_subdirectory(examples)
diff --git a/src/examples/CMakeLists.txt b/src/examples/CMakeLists.txt
deleted file mode 100644
index 67966991..00000000
--- a/src/examples/CMakeLists.txt
+++ /dev/null
@@ -1,29 +0,0 @@
-SET(BEMAN_OPTIONAL26_LIBRARY "beman_optional26")
-
-include(GNUInstallDirs)
-
-add_executable(main "")
-
-target_sources(
-  main
-  PRIVATE
-  main.cpp
-)
-
-target_link_libraries(main "${BEMAN_OPTIONAL26_LIBRARY}")
-
-add_executable(before_after "")
-
-target_sources(
-  before_after
-  PRIVATE
-  before_after.cpp
-)
-
-target_link_libraries(before_after "${BEMAN_OPTIONAL26_LIBRARY}")
-
-install(
-  TARGETS main
-  EXPORT ${TARGETS_EXPORT_NAME}
-  DESTINATION ${CMAKE_INSTALL_BINDIR}
-)
diff --git a/src/examples/main.cpp b/src/examples/main.cpp
deleted file mode 100644
index 5a5e7fd4..00000000
--- a/src/examples/main.cpp
+++ /dev/null
@@ -1,4 +0,0 @@
-#include <Beman/Optional26/optional.hpp>
-
-int main() {
-}