added beautiful unexpected

yielding · yielding · commit ea863df09a9b · 2024-08-28T23:46:59.000+09:00
diff --git a/cpp.fp/unexpected/CMakeLists.txt b/cpp.fp/unexpected/CMakeLists.txt
@@ -0,0 +1,26 @@
+cmake_minimum_required (VERSION 3.30)
+
+project (main)
+
+set (CMAKE_CXX_STANDARD 23)
+set (CMAKE_CXX_COMPILER g++-14)
+set (CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+set (SOURCES
+  main.cpp
+)
+
+include_directories (
+  /usr/local/include
+  /opt/homebrew/include
+  ${CMAKE_CURRENT_SOURCE_DIR}
+)
+
+link_directories (
+  /usr/local/lib
+  /opt/homebrew/lib
+)
+
+add_executable (main
+  ${SOURCES}
+)
diff --git a/cpp.fp/unexpected/main.cpp b/cpp.fp/unexpected/main.cpp
@@ -0,0 +1,40 @@
+#include <iostream>
+#include <expected> 
+
+using namespace std;
+
+enum class error 
+{
+  compile_time_error,
+  runtime_error
+};
+
+auto unexpected_runtime_error() -> expected<int, error>
+{
+  return unexpected(error::runtime_error);
+}
+
+int main(int argc, char* argv[])
+{
+  expected<double, int> ex = unexpected(3);
+
+  if (!ex) 
+    cout << "ex contains an error\n";
+
+  if (ex == unexpected(3))
+    cout << "The error value is equal to 3\n";
+
+  const auto e = unexpected_runtime_error();
+  e.and_then([](const auto& e) -> expected<int, error>
+  {
+    cout << "and_then" << int(e);
+    return {};
+  })
+  .or_else([](const auto& e) -> expected<int, error>
+  {
+    cout << "or_else: " << int(e);
+    return {};
+  });
+
+  return 0;
+}
diff --git a/cpp.unicode/string/convert.cpp b/cpp.unicode/string/convert.cpp
@@ -22,7 +22,6 @@ int main(int argc, const char *argv[])
 
 
   // 2. to ucs2
-
   wstring_convert<codecvt_utf8<char16_t>, char16_t> ucs2conv;
   try 
   {
@@ -35,7 +34,6 @@ int main(int argc, const char *argv[])
       << " characters:\n";
 
     for (char16_t c : ucs2) cout << hex << showbase << c << '\n';
-
   }
 
   return 0;

Original file line number	Diff line number	Diff line change
`@@ -22,7 +22,6 @@ int main(int argc, const char *argv[])`
`22`	`22`
`23`	`23`
`24`	`24`	`// 2. to ucs2`
`25`		`-`
`26`	`25`	`wstring_convert<codecvt_utf8<char16_t>, char16_t> ucs2conv;`
`27`	`26`	`try`
`28`	`27`	`{`
`@@ -35,7 +34,6 @@ int main(int argc, const char *argv[])`
`35`	`34`	`<< " characters:\n";`
`36`	`35`
`37`	`36`	`for (char16_t c : ucs2) cout << hex << showbase << c << '\n';`
`38`		`-`
`39`	`37`	`}`
`40`	`38`
`41`	`39`	`return 0;`