command_line: allow args to depend on more than one args

src/common/command_line.h

@@ -33,6 +33,7 @@
 #include <functional>
 #include <iostream>
 #include <sstream>
+#include <array>
 #include <type_traits>
 
 #include <boost/program_options/parsers.hpp>
@@ -48,7 +49,7 @@ namespace command_line
   //! \return True if `str` is `is_iequal("n" || "no" || `tr("no"))`.
   bool is_no(const std::string& str);
 
-  template<typename T, bool required = false, bool dependent = false>
+  template<typename T, bool required = false, bool dependent = false, int NUM_DEPS = 1>
   struct arg_descriptor;
 
   template<typename T>
@@ -98,6 +99,22 @@ namespace command_line
     bool not_use_default;
   };
 
+  template<typename T, int NUM_DEPS>
+  struct arg_descriptor<T, false, true, NUM_DEPS>
+  {
+    typedef T value_type;
+
+    const char* name;
+    const char* description;
+
+    T default_value;
+
+    std::array<const arg_descriptor<bool, false> *, NUM_DEPS> ref;
+    std::function<T(std::array<bool, NUM_DEPS>, bool, T)> depf;
+
+    bool not_use_default;
+  };
+
   template<typename T>
   boost::program_options::typed_value<T, char>* make_semantic(const arg_descriptor<T, true>& /*arg*/)
   {
@@ -127,6 +144,28 @@ namespace command_line
     return semantic;
   }
 
+  template<typename T, int NUM_DEPS>
+  boost::program_options::typed_value<T, char>* make_semantic(const arg_descriptor<T, false, true, NUM_DEPS>& arg)
+  {
+    auto semantic = boost::program_options::value<T>();
+    if (!arg.not_use_default) {
+      std::array<bool, NUM_DEPS> depval;
+      depval.fill(false);
+      std::ostringstream format;
+      format << arg.depf(depval, true, arg.default_value);
+      for (size_t i = 0; i < depval.size(); ++i)
+      {
+        depval.fill(false);
+        depval[i] = true;
+        format << ", " << arg.depf(depval, true, arg.default_value) << " if '" << arg.ref[i]->name << "'";
+      }
+      for (size_t i = 0; i < depval.size(); ++i)
+        depval[i] = arg.ref[i]->default_value;
+      semantic->default_value(arg.depf(depval, true, arg.default_value), format.str());
+    }
+    return semantic;
+  }
+
   template<typename T>
   boost::program_options::typed_value<T, char>* make_semantic(const arg_descriptor<T, false>& arg, const T& def)
   {
@@ -144,8 +183,8 @@ namespace command_line
     return semantic;
   }
 
-  template<typename T, bool required, bool dependent>
-  void add_arg(boost::program_options::options_description& description, const arg_descriptor<T, required, dependent>& arg, bool unique = true)
+  template<typename T, bool required, bool dependent, int NUM_DEPS>
+  void add_arg(boost::program_options::options_description& description, const arg_descriptor<T, required, dependent, NUM_DEPS>& arg, bool unique = true)
   {
     if (0 != description.find_nothrow(arg.name, false))
     {
@@ -214,15 +253,15 @@ namespace command_line
     }
   }
 
-  template<typename T, bool required, bool dependent>
-  typename std::enable_if<!std::is_same<T, bool>::value, bool>::type has_arg(const boost::program_options::variables_map& vm, const arg_descriptor<T, required, dependent>& arg)
+  template<typename T, bool required, bool dependent, int NUM_DEPS>
+  typename std::enable_if<!std::is_same<T, bool>::value, bool>::type has_arg(const boost::program_options::variables_map& vm, const arg_descriptor<T, required, dependent, NUM_DEPS>& arg)
   {
     auto value = vm[arg.name];
     return !value.empty();
   }
 
-  template<typename T, bool required, bool dependent>
-  bool is_arg_defaulted(const boost::program_options::variables_map& vm, const arg_descriptor<T, required, dependent>& arg)
+  template<typename T, bool required, bool dependent, int NUM_DEPS>
+  bool is_arg_defaulted(const boost::program_options::variables_map& vm, const arg_descriptor<T, required, dependent, NUM_DEPS>& arg)
   {
     return vm[arg.name].defaulted();
   }
@@ -233,14 +272,23 @@ namespace command_line
     return arg.depf(get_arg(vm, arg.ref), is_arg_defaulted(vm, arg), vm[arg.name].template as<T>());
   }
 
+  template<typename T, int NUM_DEPS>
+  T get_arg(const boost::program_options::variables_map& vm, const arg_descriptor<T, false, true, NUM_DEPS>& arg)
+  {
+    std::array<bool, NUM_DEPS> depval;
+    for (size_t i = 0; i < depval.size(); ++i)
+      depval[i] = get_arg(vm, *arg.ref[i]);
+    return arg.depf(depval, is_arg_defaulted(vm, arg), vm[arg.name].template as<T>());
+  }
+
   template<typename T, bool required>
   T get_arg(const boost::program_options::variables_map& vm, const arg_descriptor<T, required>& arg)
   {
     return vm[arg.name].template as<T>();
   }
  
-  template<bool dependent>
-  inline bool has_arg(const boost::program_options::variables_map& vm, const arg_descriptor<bool, false, dependent>& arg)
+  template<bool dependent, int NUM_DEPS>
+  inline bool has_arg(const boost::program_options::variables_map& vm, const arg_descriptor<bool, false, dependent, NUM_DEPS>& arg)
   {
     return get_arg(vm, arg);
   }