Adding simple flag callback (#33)

* Addind simple flag callback * Give flag function a new name, old name only on C++14 * Fixing reference to destroyed function * Better GCC 4.7 support, travis prepared for C++17 (not used yet) * Updating documentation

Adding simple flag callback (#33)
* Addind simple flag callback * Give flag function a new name, old name only on C++14 * Fixing reference to destroyed function * Better GCC 4.7 support, travis prepared for C++17 (not used yet) * Updating documentation
Henry Schreiner · GitHub
1 parent adbd2aa7
Showing 8 changed files with 106 additions and 3 deletions
.ci/travis.sh
.travis.yml
CHANGELOG.md
CMakeLists.txt
README.md
include/CLI/App.hpp
include/CLI/Timer.hpp
tests/AppTest.cpp
@@ -3,8 +3,18 @@ set -evx
  
 mkdir build || true
 cd build
-cmake .. -DCLI_SINGLE_FILE_TESTS=ON -DCMAKE_BUILD_TYPE=Debug
+cmake .. -DCLI_CXX_STD=11 -DCLI_SINGLE_FILE_TESTS=ON -DCMAKE_BUILD_TYPE=Debug
 cmake --build . -- -j2
 ctest --output-on-failure
+if [ -n "$CLI_CXX_STD" ] && [ "$CLI_CXX_STD" -ge "14" ] ; then
+    cmake .. -DCLI_CXX_STD=14 -DCLI_SINGLE_FILE_TESTS=ON -DCMAKE_BUILD_TYPE=Debug
+    cmake --build . -- -j2
+    ctest --output-on-failure
+fi
+if [ -n "$CLI_CXX_STD" ] && [ "$CLI_CXX_STD" -ge "17" ] ; then
+    cmake .. -DCLI_CXX_STD=17 -DCLI_SINGLE_FILE_TESTS=ON -DCMAKE_BUILD_TYPE=Debug
+    cmake --build . -- -j2
+    ctest --output-on-failure
+fi
  
 set +evx
@@ -20,6 +20,7 @@ matrix:
     env:
     - COMPILER=3.9
     - CHECK_STYLE=yes
+    - CLI_CXX_STD=14
   - compiler: clang
     addons:
       apt:
@@ -41,6 +42,7 @@ matrix:
     env:
     - COMPILER=6
     - COVERALLS=yes
+    - CLI_CXX_STD=14
   - compiler: gcc
     addons:
       apt:
@@ -48,7 +50,6 @@ matrix:
         - g++-4.7
     env:
     - COMPILER=4.7
-    - CXXFLAGS=-D_GLIBCXX_USE_NANOSLEEP
   - os: osx
 install:
 - python -c 'import sys; print(sys.version_info[:])'
 ## Version 1.2 (in progress)
  
+* Added functional form of flag [#33](https://github.com/CLIUtils/CLI11/pull/33), automatic on C++14
 * Fixed Config file search if passed on command line [#30](https://github.com/CLIUtils/CLI11/issues/30)
 * Added `CLI11_PARSE(app, argc, argv)` macro for simple parse commands (does not support returning arg)
 * The name string can now contain spaces around commas [#29](https://github.com/CLIUtils/CLI11/pull/29)
@@ -4,9 +4,11 @@ project(CLI11 CXX)
  
 SET(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})
  
+set(CLI_CXX_STD "11"  CACHE STRING "The CMake standard to require")
+
 if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
     set(CUR_PROJ ON)
-    set(CMAKE_CXX_STANDARD 11)
+    set(CMAKE_CXX_STANDARD ${CLI_CXX_STD})
     set(CMAKE_CXX_EXTENSIONS OFF)
     set(CMAKE_CXX_STANDARD_REQUIRED ON)
  
@@ -120,6 +120,10 @@ app.add_flag(option_name,
              int_or_bool = nothing,
              help_string="")
  
+app.add_flag_function(option_name,
+             function <void(size_t count)>,
+             help_string="")
+
 app.add_set(option_name,
             variable_to_bind_to,
             set_of_possible_options,
@@ -133,6 +137,8 @@ App* subcom = app.add_subcommand(name, discription);
  
 An option name must start with a alphabetic character or underscore. For long options, anything but an equals sign or a comma is valid after that. Names are given as a comma separated string, with the dash or dashes. An option or flag can have as many names as you want, and afterward, using `count`, you can use any of the names, with dashes as needed, to count the options. One of the names is allowed to be given without proceeding dash(es); if present the option is a positional option, and that name will be used on help line for its positional form. If you want the default value to print in the help description, pass in `true` for the final parameter for `add_option` or `add_set`. The set options allow your users to pick from a set of predefined options.
  
+On a C++14 compiler, you can pass a callback function directly to `.add_flag`, while in C++11 mode you'll need to use `.add_flag_function` if you want a callback function. The function will be given the number of times the flag was passed. You can throw a `CLI::ParseError` to signal a failure.
+
 ### Example
  
 * `"one,-o,--one"`: Valid as long as not a flag, would create an option that can be specified positionally, or with `-o` or `--one`
@@ -370,6 +370,33 @@ class App {
         return opt;
     }
  
+    /// Add option for callback
+    Option *add_flag_function(std::string name,
+                              std::function<void(size_t)> function, ///< A function to call, void(size_t)
+                              std::string description = "") {
+
+        CLI::callback_t fun = [function](CLI::results_t res) {
+            auto count = static_cast<size_t>(res.size());
+            function(count);
+            return true;
+        };
+
+        Option *opt = add_option(name, fun, description, false);
+        if(opt->get_positional())
+            throw IncorrectConstruction("Flags cannot be positional");
+        opt->set_custom_option("", 0);
+        return opt;
+    }
+
+#if __cplusplus >= 201402L
+    /// Add option for callback (C++14 or better only)
+    Option *add_flag(std::string name,
+                     std::function<void(size_t)> function, ///< A function to call, void(size_t)
+                     std::string description = "") {
+        return add_flag_function(name, function, description);
+    }
+#endif
+
     /// Add set of options (No default)
     template <typename T>
     Option *add_set(std::string name,
@@ -3,6 +3,12 @@
 // Distributed under the 3-Clause BSD License.  See accompanying
 // file LICENSE or https://github.com/CLIUtils/CLI11 for details.
  
+// On GCC < 4.8, the following define is often missing. Due to the
+// fact that this library only uses sleep_for, this should be safe
+#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ < 5 && __GNUC_MINOR__ < 8
+#define _GLIBCXX_USE_NANOSLEEP
+#endif
+
 #include <chrono>
 #include <functional>
 #include <iostream>
@@ -243,6 +243,56 @@ TEST_F(TApp, RequiredFlags) {
     run();
 }
  
+TEST_F(TApp, CallbackFlags) {
+
+    int value = 0;
+
+    auto func = [&value](size_t x) { value = x; };
+
+    app.add_flag_function("-v", func);
+
+    run();
+    EXPECT_EQ(value, 0);
+
+    app.reset();
+    args = {"-v"};
+    run();
+    EXPECT_EQ(value, 1);
+
+    app.reset();
+    args = {"-vv"};
+    run();
+    EXPECT_EQ(value, 2);
+
+    EXPECT_THROW(app.add_flag_function("hi", func), CLI::IncorrectConstruction);
+}
+
+#if __cplusplus >= 201402L
+TEST_F(TApp, CallbackFlagsAuto) {
+
+    int value = 0;
+
+    auto func = [&value](size_t x) { value = x; };
+
+    app.add_flag("-v", func);
+
+    run();
+    EXPECT_EQ(value, 0);
+
+    app.reset();
+    args = {"-v"};
+    run();
+    EXPECT_EQ(value, 1);
+
+    app.reset();
+    args = {"-vv"};
+    run();
+    EXPECT_EQ(value, 2);
+
+    EXPECT_THROW(app.add_flag("hi", func), CLI::IncorrectConstruction);
+}
+#endif
+
 TEST_F(TApp, Positionals) {
  
     std::string posit1;