[lmi] access to mc_enum type information [patch 1/3]

[Vaclav Slavik]

Hi,

I've hit a small problem when implementing inline editing of cell values in
CensusView: I need to know the type of values displayed in given column, in
order to determine what the appropriate editor control is. For example,
enums should use a wxChoice control, boolean values should use checkboxes,
input sequences should use their own editor etc.

This information is exposed via any_member<>::type(), but that's not enough
for me, unfortunately: I need to identify all enums or tn_range types and it's
impractical to test for every type derived from mc_enum_base. And I can't use
member_cast<mc_enum_base>, because it throws on failure.

Here's a series of three patches that together address this problem; with
them, I'm able to create appropriate wxChoice control for any mc_enum<>
field. Are these changes OK?

Thanks,
Vaclav


[PATCH 1/3] Add virtual mc_enum_base::get_all_strings().

This is a companion to static mc_enum<T>::all_strings() and returns
the same thing. Unlike all_strings(), it's virtual and so can be called
without knowing the exact enum type.
---
 ce_product_name.cpp |    5 +++++
 ce_product_name.hpp |    2 ++
 mc_enum.hpp         |    3 +++
 mc_enum.tpp         |    6 ++++++
 4 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/ce_product_name.cpp b/ce_product_name.cpp
index ce5b523..16678ac 100644
--- a/ce_product_name.cpp
+++ b/ce_product_name.cpp
@@ -114,6 +114,11 @@ std::vector<std::string> const& 
ce_product_name::product_names()
     return ::product_names();
 }
 
+std::vector<std::string> const& ce_product_name::get_all_strings() const
+{
+    return product_names();
+}
+
 std::istream& ce_product_name::read(std::istream& is)
 {
     std::locale old_locale = is.imbue(blank_is_not_whitespace_locale());
diff --git a/ce_product_name.hpp b/ce_product_name.hpp
index 809a11b..213471a 100644
--- a/ce_product_name.hpp
+++ b/ce_product_name.hpp
@@ -89,6 +89,8 @@ class ce_product_name
     std::string str() const;
     std::string value() const;
 
+    virtual std::vector<std::string> const& get_all_strings() const;
+
   private:
     static std::vector<std::string> const& product_names();
 
diff --git a/mc_enum.hpp b/mc_enum.hpp
index 8c3ef92..6fea532 100644
--- a/mc_enum.hpp
+++ b/mc_enum.hpp
@@ -71,6 +71,8 @@ class LMI_SO mc_enum_base
     virtual std::size_t ordinal() const = 0;
     virtual std::string str(int) const = 0;
 
+    virtual std::vector<std::string> const& get_all_strings() const = 0;
+
   private:
     std::deque<bool> allowed_;
 };
@@ -129,6 +131,7 @@ class mc_enum
     T value() const;
 
     static std::vector<std::string> const& all_strings();
+    virtual std::vector<std::string> const& get_all_strings() const;
 
   private:
     static std::size_t        n();
diff --git a/mc_enum.tpp b/mc_enum.tpp
index d8ab517..269b723 100644
--- a/mc_enum.tpp
+++ b/mc_enum.tpp
@@ -236,3 +236,9 @@ std::vector<std::string> const& mc_enum<T>::all_strings()
     return v;
 }
 
+template<typename T>
+std::vector<std::string> const& mc_enum<T>::get_all_strings() const
+{
+    return all_strings();
+}
+