Add support for size_t to wxConfig

Allow writing and reading size_t values directly too, there were not
previously accepted unlike all the other arithmetic types.

Closes #19091.

include/wx/confbase.h

@@ -192,6 +192,9 @@ public:
   bool Read(const wxString& key, wxLongLong_t *pl, wxLongLong_t defVal) const;
 #endif // wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG
 
+  bool Read(const wxString& key, size_t* val) const;
+  bool Read(const wxString& key, size_t* val, size_t defVal) const;
+
 #if wxUSE_BASE64
     // read a binary data block
   bool Read(const wxString& key, wxMemoryBuffer* data) const

interface/wx/config.h

@@ -571,7 +571,29 @@ public:
         @endWxPerlOnly
     */
     bool Read(const wxString& key, wxLongLong_t* ll,
-              wxLongLong_t defaultVal) const;
+    /**
+        Reads a size_t value, returning @true if the value was found.
+        If the value was not found, @a value is not changed.
+
+        @since 3.1.5
+
+        @beginWxPerlOnly
+        Not supported by wxPerl.
+        @endWxPerlOnly
+    */
+    bool Read(const wxString& key, size_t* value) const;
+    /**
+        Reads a size_t value, returning @true if the value was found.
+        If the value was not found, @a defaultVal is used instead.
+
+        @since 3.1.5
+
+        @beginWxPerlOnly
+        Not supported by wxPerl.
+        @endWxPerlOnly
+    */
+    bool Read(const wxString& key, size_t* value,
+              size_t defaultVal) const;
     /**
         Reads a double value, returning @true if the value was found. If the
         value was not found, @a d is not changed.

src/common/config.cpp

@@ -177,6 +177,40 @@ bool wxConfigBase::Read(const wxString& key, int *pi, int defVal) const
     return r;
 }
 
+// size_t is stored either as long or long long (Win64)
+#if SIZEOF_SIZE_T == SIZEOF_LONG
+    typedef long SizeSameSizeAsSizeT;
+#elif SIZEOF_SIZE_T == SIZEOF_LONG_LONG
+    typedef wxLongLong_t SizeSameSizeAsSizeT;
+#else
+    #error Unexpected sizeof(size_t)
+#endif
+
+bool wxConfigBase::Read(const wxString& key, size_t* val) const
+{
+    wxCHECK_MSG( val, false, wxT("wxConfig::Read(): NULL parameter") );
+
+    SizeSameSizeAsSizeT tmp;
+    if ( !Read(key, &tmp) )
+        return false;
+
+    *val = static_cast<size_t>(tmp);
+    return true;
+}
+
+bool wxConfigBase::Read(const wxString& key, size_t* val, size_t defVal) const
+{
+    wxCHECK_MSG( val, false, wxT("wxConfig::Read(): NULL parameter") );
+
+    if ( !Read(key, val) )
+    {
+        *val = defVal;
+        return false;
+    }
+
+    return true;
+}
+
 // Read floats as doubles then just type cast it down.
 bool wxConfigBase::Read(const wxString& key, float* val) const
 {

tests/config/config.cpp

@@ -53,6 +53,7 @@ TEST_CASE("wxConfig::ReadWriteLocal", "[config]")
     const wxULongLong_t uval64 = wxULL(0x9000000000000009);
     config->Write("ull", uval64);
 
+    config->Write("size", size_t(UINT_MAX));
 #ifdef wxHAS_CONFIG_TEMPLATE_RW
     config->Write("color1", wxColour(11,22,33,44));
 #endif // wxHAS_CONFIG_TEMPLATE_RW
@@ -110,6 +111,10 @@ TEST_CASE("wxConfig::ReadWriteLocal", "[config]")
     CHECK( ll == static_cast<wxLongLong_t>(uval64) );
     CHECK( config->ReadLongLong("ull", 0) == static_cast<wxLongLong_t>(uval64) );
 
+    size_t size;
+    CHECK( config->Read("size", &size) );
+    CHECK( size == UINT_MAX );
+
 #ifdef wxHAS_CONFIG_TEMPLATE_RW
     wxColour color1;
     r = config->Read("color1", &color1);