Adding functional form of Type printout

include/CLI/App.hpp

@@ -538,9 +538,9 @@ class App {
         };
 
         Option *opt = add_option(name, fun, description, false);
-        std::string typeval = detail::type_name<T>();
+        opt->set_type_name(
-        typeval += " in {" + detail::join(options) + "}";
+            [&options]() { return std::string(detail::type_name<T>()) + " in {" + detail::join(options) + "}"; });
-        opt->set_custom_option(typeval);
+
         return opt;
     }
 
@@ -589,9 +589,8 @@ class App {
         };
 
         Option *opt = add_option(name, fun, description, defaulted);
-        std::string typeval = detail::type_name<T>();
+        opt->set_type_name(
-        typeval += " in {" + detail::join(options) + "}";
+            [&options]() { return std::string(detail::type_name<T>()) + " in {" + detail::join(options) + "}"; });
-        opt->set_custom_option(typeval);
         if(defaulted) {
             std::stringstream out;
             out << member;
@@ -649,9 +648,9 @@ class App {
         };
 
         Option *opt = add_option(name, fun, description, false);
-        std::string typeval = detail::type_name<std::string>();
+        opt->set_type_name([&options]() {
-        typeval += " in {" + detail::join(options) + "}";
+            return std::string(detail::type_name<std::string>()) + " in {" + detail::join(options) + "}";
-        opt->set_custom_option(typeval);
+        });
 
         return opt;
     }
@@ -709,9 +708,9 @@ class App {
         };
 
         Option *opt = add_option(name, fun, description, defaulted);
-        std::string typeval = detail::type_name<std::string>();
+        opt->set_type_name([&options]() {
-        typeval += " in {" + detail::join(options) + "}";
+            return std::string(detail::type_name<std::string>()) + " in {" + detail::join(options) + "}";
-        opt->set_custom_option(typeval);
+        });
         if(defaulted) {
             opt->set_default_str(member);
         }

include/CLI/Formatter.hpp

@@ -193,8 +193,8 @@ inline std::string Formatter::make_option_opts(const Option *opt) const {
     std::stringstream out;
 
     if(opt->get_type_size() != 0) {
-        if(!opt->get_typeval().empty())
+        if(!opt->get_type_name().empty())
-            out << " " << get_label(opt->get_typeval());
+            out << " " << get_label(opt->get_type_name());
         if(!opt->get_defaultval().empty())
             out << "=" << opt->get_defaultval();
         if(opt->get_expected() > 1)

include/CLI/Option.hpp

@@ -171,7 +171,7 @@ class Option : public OptionBase<Option> {
     std::string defaultval_;
 
     /// A human readable type value, set when App creates this
-    std::string typeval_;
+    std::function<std::string()> typeval_;
 
     /// True if this option has a default
     bool default_{false};
@@ -385,9 +385,6 @@ class Option : public OptionBase<Option> {
     /// The number of arguments the option expects
     int get_type_size() const { return type_size_; }
 
-    /// The type name (for help printing)
-    std::string get_typeval() const { return typeval_; }
-
     /// The environment variable associated to this value
     std::string get_envname() const { return envname_; }
 
@@ -612,7 +609,7 @@ class Option : public OptionBase<Option> {
 
     /// Set a custom option, typestring, type_size
     void set_custom_option(std::string typeval, int type_size = 1) {
-        typeval_ = typeval;
+        set_type_name(typeval);
         type_size_ = type_size;
         if(type_size_ == 0)
             required_ = false;
@@ -633,10 +630,15 @@ class Option : public OptionBase<Option> {
     }
 
     /// Set the type name displayed on this option
-    void set_type_name(std::string val) { typeval_ = val; }
+    void set_type_name(std::string typeval) {
+        typeval_ = [typeval]() { return typeval; };
+    }
+
+    /// Set the type function to run when displayed on this option
+    void set_type_name(std::function<std::string()> typefun) { typeval_ = typefun; }
 
     /// Get the typename for this option
-    std::string get_type_name() const { return typeval_; }
+    std::string get_type_name() const { return typeval_(); }
 };
 
 } // namespace CLI

tests/HelpTest.cpp

@@ -665,4 +665,25 @@ TEST(THelp, CombinedValidatorsPathyText) {
     std::string help = app.help();
     EXPECT_THAT(help, Not(HasSubstr("TEXT")));
     EXPECT_THAT(help, HasSubstr("PATH"));
+
+// #113 Part 2
+TEST(THelp, ChangingSet) {
+    CLI::App app;
+
+    std::set<int> vals{1, 2, 3};
+    int val;
+    app.add_set("--val", val, vals);
+
+    std::string help = app.help();
+
+    EXPECT_THAT(help, HasSubstr("1"));
+    EXPECT_THAT(help, Not(HasSubstr("4")));
+
+    vals.insert(4);
+    vals.erase(1);
+
+    help = app.help();
+
+    EXPECT_THAT(help, Not(HasSubstr("1")));
+    EXPECT_THAT(help, HasSubstr("4"));
 }