Deserialize scalars (#14)

Co-authored-by: Dirkjan Ochtman <dirkjan@ochtman.nl>

instant-xml-macros/src/de.rs

@@ -1,5 +1,5 @@
 use proc_macro2::{Ident, Span, TokenStream};
-use quote::quote;
+use quote::{quote, ToTokens};
 
 use crate::{get_namespaces, retrieve_field_attribute, FieldAttribute};
 
@@ -34,6 +34,25 @@ impl quote::ToTokens for Deserializer {
 impl Deserializer {
     pub fn new(input: &syn::DeriveInput) -> Deserializer {
         let ident = &input.ident;
+        let generics = (&input.generics).into_token_stream();
+        let lifetimes = (&input.generics.params).into_token_stream();
+
+        let mut lifetime_xml = TokenStream::new();
+        let mut lifetime_visitor = TokenStream::new();
+        let iter = &mut input.generics.params.iter();
+        if let Some(it) = iter.next() {
+            lifetime_xml = quote!(:);
+            lifetime_xml.extend(it.into_token_stream());
+            while let Some(it) = iter.by_ref().next() {
+                lifetime_xml.extend(quote!(+));
+                lifetime_xml.extend(it.into_token_stream());
+            }
+            lifetime_xml.extend(quote!(,));
+            lifetime_xml.extend(lifetimes.clone());
+            lifetime_visitor.extend(quote!(,));
+            lifetime_visitor.extend(lifetimes);
+        }
+
         let name = ident.to_string();
         let mut out = TokenStream::new();
 
@@ -113,7 +132,7 @@ impl Deserializer {
         let attr_type_match = attributes_tokens.match_;
 
         out.extend(quote!(
-            fn deserialize(deserializer: &mut ::instant_xml::Deserializer) -> Result<Self, ::instant_xml::Error> {
+            fn deserialize(deserializer: &mut ::instant_xml::Deserializer<'xml>) -> Result<Self, ::instant_xml::Error> {
                 use ::instant_xml::parse::XmlRecord;
                 use ::instant_xml::{Error, Deserializer, Visitor} ;
 
@@ -143,12 +162,18 @@ impl Deserializer {
                     }
                 }
 
-                struct StructVisitor;
-                impl<'xml> Visitor<'xml> for StructVisitor {
-                    type Value = #ident;
+                struct StructVisitor<'xml #lifetime_xml> {
+                    marker: std::marker::PhantomData<#ident #generics>,
+                    lifetime: std::marker::PhantomData<&'xml ()>,
+                }
 
-                    fn visit_struct<'a>(&self, deserializer: &mut ::instant_xml::Deserializer) -> Result<Self::Value, ::instant_xml::Error>
-                    {
+                impl<'xml #lifetime_xml> Visitor<'xml> for StructVisitor<'xml #lifetime_visitor> {
+                    type Value = #ident #generics;
+
+                    fn visit_struct(
+                        &self,
+                        deserializer: &mut ::instant_xml::Deserializer<'xml>
+                    ) -> Result<Self::Value, ::instant_xml::Error> {
                         #declare_values
                         while let Some(( key, _ )) = deserializer.peek_next_attribute() {
                             match get_attribute(&key) {
@@ -181,7 +206,15 @@ impl Deserializer {
                 }
 
                 #namespaces_map;
-                deserializer.deserialize_struct(StructVisitor{}, #name, #default_namespace, &namespaces_map)
+                deserializer.deserialize_struct(
+                    StructVisitor{
+                        marker: std::marker::PhantomData,
+                        lifetime: std::marker::PhantomData
+                    },
+                    #name,
+                    #default_namespace,
+                    &namespaces_map
+                )
             }
         ));
 
@@ -189,6 +222,12 @@ impl Deserializer {
             const TAG_NAME: ::instant_xml::TagName<'xml> = ::instant_xml::TagName::Custom(#name);
         ));
 
+        out = quote!(
+            impl<'xml #lifetime_xml> FromXml<'xml> for #ident #generics {
+                #out
+            }
+        );
+
         Deserializer { out }
     }
 
@@ -206,16 +245,14 @@ impl Deserializer {
         let field_var = field.ident.as_ref().unwrap();
         let field_var_str = field_var.to_string();
         let const_field_var_str = Ident::new(&field_var_str.to_uppercase(), Span::call_site());
-        let field_type = match &field.ty {
-            syn::Type::Path(v) => v.path.get_ident(),
-            _ => panic!("Wrong field attribute format"),
-        };
+        let mut no_lifetime_type = field.ty.clone();
+        discard_lifetimes(&mut no_lifetime_type);
 
         let enum_name = Ident::new(&format!("__Value{index}"), Span::call_site());
         tokens.enum_.extend(quote!(#enum_name,));
 
         tokens.consts.extend(quote!(
-            const #const_field_var_str: &str = match #field_type::TAG_NAME {
+            const #const_field_var_str: &str = match <#no_lifetime_type>::TAG_NAME {
                 ::instant_xml::TagName::FieldName => #field_var_str,
                 ::instant_xml::TagName::Custom(v) => v,
             };
@@ -232,7 +269,7 @@ impl Deserializer {
         }
 
         declare_values.extend(quote!(
-            let mut #enum_name: Option<#field_type> = None;
+            let mut #enum_name: Option<#no_lifetime_type> = None;
         ));
 
         let def_prefix = match def_prefix {
@@ -283,7 +320,7 @@ impl Deserializer {
                     }
                     #field_namespace
                     deserializer.set_next_def_namespace(field_namespace)?;
-                    #enum_name = Some(#field_type::deserialize(deserializer)?);
+                    #enum_name = Some(<#no_lifetime_type>::deserialize(deserializer)?);
                 },
             ));
         } else {
@@ -294,13 +331,53 @@ impl Deserializer {
                     }
 
                     deserializer.set_next_type_as_attribute()?;
-                    #enum_name = Some(#field_type::deserialize(deserializer)?);
+                    #enum_name = Some(<#no_lifetime_type>::deserialize(deserializer)?);
                 },
             ));
         }
 
         return_val.extend(quote!(
-            #field_var: #enum_name.expect("Expected some value"),
+            #field_var: match #enum_name {
+                Some(v) => v,
+                None => <#no_lifetime_type>::missing_value()?,
+            },
         ));
     }
 }
+
+fn discard_lifetimes(ty: &mut syn::Type) {
+    match ty {
+        syn::Type::Path(ty) => discard_path_lifetimes(ty),
+        syn::Type::Reference(ty) => {
+            ty.lifetime = None;
+            discard_lifetimes(&mut ty.elem);
+        }
+        _ => {}
+    }
+}
+
+fn discard_path_lifetimes(path: &mut syn::TypePath) {
+    if let Some(q) = &mut path.qself {
+        discard_lifetimes(&mut q.ty);
+    }
+
+    for segment in &mut path.path.segments {
+        match &mut segment.arguments {
+            syn::PathArguments::None => {}
+            syn::PathArguments::AngleBracketed(args) => {
+                args.args.iter_mut().for_each(|arg| match arg {
+                    syn::GenericArgument::Lifetime(lt) => {
+                        *lt = syn::Lifetime::new("'_", Span::call_site())
+                    }
+                    syn::GenericArgument::Type(ty) => discard_lifetimes(ty),
+                    syn::GenericArgument::Binding(_)
+                    | syn::GenericArgument::Constraint(_)
+                    | syn::GenericArgument::Const(_) => {}
+                })
+            }
+            syn::PathArguments::Parenthesized(args) => {
+                args.inputs.iter_mut().for_each(discard_lifetimes)
+            }
+        }
+    }
+}

instant-xml-macros/src/lib.rs

@@ -168,12 +168,9 @@ pub fn to_xml(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
 #[proc_macro_derive(FromXml, attributes(xml))]
 pub fn from_xml(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
     let ast = parse_macro_input!(input as syn::DeriveInput);
-    let ident = &ast.ident;
-
     let deserializer = de::Deserializer::new(&ast);
+
     proc_macro::TokenStream::from(quote!(
-        impl<'xml> FromXml<'xml> for #ident {
-            #deserializer
-        }
+        #deserializer
     ))
 }

instant-xml/src/impls.rs

@@ -1,17 +1,25 @@
 use std::borrow::Cow;
 use std::fmt;
+use std::marker::PhantomData;
 use std::str::FromStr;
 
 use crate::{
     Deserializer, EntityType, Error, FieldAttribute, FromXml, Serializer, TagName, ToXml, Visitor,
 };
 
-struct BoolVisitor;
+// Deserializer
+struct FromStrToVisitor<T: FromStr>(PhantomData<T>)
+where
+    T: FromStr,
+    <T as FromStr>::Err: std::fmt::Display;
 
-impl<'de> Visitor<'de> for BoolVisitor {
-    type Value = bool;
-
-    fn visit_str<'a>(self, value: &str) -> Result<Self::Value, Error> {
+impl<'xml, T> Visitor<'xml> for FromStrToVisitor<T>
+where
+    T: FromStr,
+    <T as FromStr>::Err: std::fmt::Display,
+{
+    type Value = T;
+    fn visit_str(self, value: &str) -> Result<Self::Value, Error> {
         match FromStr::from_str(value) {
             Ok(v) => Ok(v),
             Err(e) => Err(Error::Other(e.to_string())),
@@ -19,12 +27,22 @@ impl<'de> Visitor<'de> for BoolVisitor {
     }
 }
 
+struct BoolVisitor;
+
+impl<'xml> Visitor<'xml> for BoolVisitor {
+    type Value = bool;
+
+    fn visit_str(self, value: &str) -> Result<Self::Value, Error> {
+        FromStrToVisitor(PhantomData::<Self::Value>).visit_str(value)
+    }
+}
+
 impl<'xml> FromXml<'xml> for bool {
     const TAG_NAME: TagName<'xml> = TagName::FieldName;
 
     fn deserialize(deserializer: &mut Deserializer) -> Result<Self, Error> {
         match deserializer.consume_next_type() {
-            EntityType::Element => deserializer.deserialize_bool(BoolVisitor),
+            EntityType::Element => deserializer.deserialize_element(BoolVisitor),
             EntityType::Attribute => deserializer.deserialize_attribute(BoolVisitor),
         }
     }
@@ -73,6 +91,223 @@ macro_rules! to_xml_for_number {
     };
 }
 
+struct NumberVisitor<T>
+where
+    T: FromStr,
+    <T as FromStr>::Err: std::fmt::Display,
+{
+    marker: PhantomData<T>,
+}
+
+impl<'xml, T> Visitor<'xml> for NumberVisitor<T>
+where
+    T: FromStr,
+    <T as FromStr>::Err: std::fmt::Display,
+{
+    type Value = T;
+
+    fn visit_str(self, value: &str) -> Result<Self::Value, Error> {
+        FromStrToVisitor(PhantomData::<Self::Value>).visit_str(value)
+    }
+}
+
+macro_rules! from_xml_for_number {
+    ($typ:ty) => {
+        impl<'xml> FromXml<'xml> for $typ {
+            const TAG_NAME: TagName<'xml> = TagName::FieldName;
+
+            fn deserialize(deserializer: &mut Deserializer) -> Result<Self, Error> {
+                match deserializer.consume_next_type() {
+                    EntityType::Element => deserializer.deserialize_element(NumberVisitor {
+                        marker: PhantomData,
+                    }),
+                    EntityType::Attribute => deserializer.deserialize_attribute(NumberVisitor {
+                        marker: PhantomData,
+                    }),
+                }
+            }
+        }
+    };
+}
+
+from_xml_for_number!(i8);
+from_xml_for_number!(i16);
+from_xml_for_number!(i32);
+from_xml_for_number!(i64);
+from_xml_for_number!(isize);
+from_xml_for_number!(u8);
+from_xml_for_number!(u16);
+from_xml_for_number!(u32);
+from_xml_for_number!(u64);
+from_xml_for_number!(usize);
+from_xml_for_number!(f32);
+from_xml_for_number!(f64);
+
+struct StringVisitor;
+
+impl<'xml> Visitor<'xml> for StringVisitor {
+    type Value = String;
+
+    fn visit_str(self, value: &str) -> Result<Self::Value, Error> {
+        Ok(escape_back(value).into_owned())
+    }
+}
+
+impl<'xml> FromXml<'xml> for String {
+    const TAG_NAME: TagName<'xml> = TagName::FieldName;
+
+    fn deserialize(deserializer: &mut Deserializer) -> Result<Self, Error> {
+        //<&'xml str>::deserialize(deserializer);
+        match deserializer.consume_next_type() {
+            EntityType::Element => deserializer.deserialize_element(StringVisitor),
+            EntityType::Attribute => deserializer.deserialize_attribute(StringVisitor),
+        }
+    }
+}
+
+struct CharVisitor;
+
+impl<'xml> Visitor<'xml> for CharVisitor {
+    type Value = char;
+
+    fn visit_str(self, value: &str) -> Result<Self::Value, Error> {
+        match value.len() {
+            1 => Ok(value.chars().next().expect("char type")),
+            _ => Err(Error::Other("Expected char type".to_string())),
+        }
+    }
+}
+
+impl<'xml> FromXml<'xml> for char {
+    const TAG_NAME: TagName<'xml> = TagName::FieldName;
+
+    fn deserialize(deserializer: &mut Deserializer) -> Result<Self, Error> {
+        match deserializer.consume_next_type() {
+            EntityType::Element => deserializer.deserialize_element(CharVisitor),
+            EntityType::Attribute => deserializer.deserialize_attribute(CharVisitor),
+        }
+    }
+}
+
+struct StrVisitor;
+
+impl<'a> Visitor<'a> for StrVisitor {
+    type Value = &'a str;
+
+    fn visit_str(self, value: &'a str) -> Result<Self::Value, Error> {
+        match escape_back(value) {
+            Cow::Owned(v) => Err(Error::Other(format!("Unsupported char: {}", v))),
+            Cow::Borrowed(v) => Ok(v),
+        }
+    }
+}
+
+impl<'xml> FromXml<'xml> for &'xml str {
+    const TAG_NAME: TagName<'xml> = TagName::FieldName;
+
+    fn deserialize(deserializer: &mut Deserializer<'xml>) -> Result<Self, Error> {
+        match deserializer.consume_next_type() {
+            EntityType::Element => deserializer.deserialize_element(StrVisitor),
+            EntityType::Attribute => deserializer.deserialize_attribute(StrVisitor),
+        }
+    }
+}
+
+struct CowStrVisitor;
+
+impl<'a> Visitor<'a> for CowStrVisitor {
+    type Value = Cow<'a, str>;
+
+    fn visit_str(self, value: &'a str) -> Result<Self::Value, Error> {
+        Ok(escape_back(value))
+    }
+}
+
+impl<'xml> FromXml<'xml> for Cow<'xml, str> {
+    const TAG_NAME: TagName<'xml> = <&str>::TAG_NAME;
+
+    fn deserialize(deserializer: &mut Deserializer<'xml>) -> Result<Self, Error> {
+        match deserializer.consume_next_type() {
+            EntityType::Element => deserializer.deserialize_element(CowStrVisitor),
+            EntityType::Attribute => deserializer.deserialize_attribute(CowStrVisitor),
+        }
+    }
+}
+
+impl<'xml, T> FromXml<'xml> for Option<T>
+where
+    T: FromXml<'xml>,
+{
+    const TAG_NAME: TagName<'xml> = <T>::TAG_NAME;
+
+    fn deserialize(deserializer: &mut Deserializer<'xml>) -> Result<Self, Error> {
+        match <T>::deserialize(deserializer) {
+            Ok(v) => Ok(Some(v)),
+            Err(e) => Err(e),
+        }
+    }
+
+    fn missing_value() -> Result<Self, Error> {
+        Ok(None)
+    }
+}
+
+fn escape_back(input: &str) -> Cow<'_, str> {
+    let mut result = String::with_capacity(input.len());
+    let input_len = input.len();
+
+    let mut last_end = 0;
+    while input_len - last_end >= 4 {
+        match &input[last_end..(last_end + 4)] {
+            "&lt;" => {
+                result.push('<');
+                last_end += 4;
+                continue;
+            }
+            "&gt;" => {
+                result.push('>');
+                last_end += 4;
+                continue;
+            }
+            _ => (),
+        };
+
+        if input_len - last_end >= 5 {
+            if &input[last_end..(last_end + 5)] == "&amp;" {
+                result.push('&');
+                last_end += 5;
+                continue;
+            }
+
+            if input_len - last_end >= 6 {
+                match &input[last_end..(last_end + 6)] {
+                    "&apos;" => {
+                        result.push('\'');
+                        last_end += 6;
+                        continue;
+                    }
+                    "&quot;" => {
+                        result.push('"');
+                        last_end += 6;
+                        continue;
+                    }
+                    _ => (),
+                };
+            }
+        }
+
+        result.push_str(input.get(last_end..last_end + 1).unwrap());
+        last_end += 1;
+    }
+
+    result.push_str(input.get(last_end..).unwrap());
+    if result.len() == input.len() {
+        return Cow::Borrowed(input);
+    }
+
+    Cow::Owned(result)
+}
+
 to_xml_for_number!(i8);
 to_xml_for_number!(i16);
 to_xml_for_number!(i32);

instant-xml/src/lib.rs

@@ -198,22 +198,28 @@ pub enum TagName<'xml> {
 pub trait FromXml<'xml>: Sized {
     const TAG_NAME: TagName<'xml>;
 
-    fn from_xml(input: &str) -> Result<Self, Error> {
+    fn from_xml(input: &'xml str) -> Result<Self, Error> {
         let mut deserializer = Deserializer::new(input);
         Self::deserialize(&mut deserializer)
     }
 
-    fn deserialize(deserializer: &mut Deserializer) -> Result<Self, Error>;
+    fn deserialize(deserializer: &mut Deserializer<'xml>) -> Result<Self, Error>;
+
+    // If the missing field is of type `Option<T>` then treat is as `None`,
+    // otherwise it is an error.
+    fn missing_value() -> Result<Self, Error> {
+        Err(Error::MissingValue)
+    }
 }
 
 pub trait Visitor<'xml>: Sized {
     type Value;
 
-    fn visit_str(self, _value: &str) -> Result<Self::Value, Error> {
+    fn visit_str(self, _value: &'xml str) -> Result<Self::Value, Error> {
         unimplemented!();
     }
 
-    fn visit_struct<'a>(&self, _deserializer: &'a mut Deserializer) -> Result<Self::Value, Error> {
+    fn visit_struct(&self, _deserializer: &mut Deserializer<'xml>) -> Result<Self::Value, Error> {
         unimplemented!();
     }
 }
@@ -373,7 +379,7 @@ impl<'xml> Deserializer<'xml> {
         ret
     }
 
-    fn deserialize_bool<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+    fn deserialize_element<V>(&mut self, visitor: V) -> Result<V::Value, Error>
     where
         V: Visitor<'xml>,
     {
@@ -422,11 +428,6 @@ impl<'xml> Deserializer<'xml> {
 
 pub trait FromXmlOwned: for<'xml> FromXml<'xml> {}
 
-#[allow(dead_code)]
-struct State<'a> {
-    prefix: HashMap<&'a str, &'a str>,
-}
-
 #[derive(Debug, Error, PartialEq, Eq)]
 pub enum Error {
     #[error("format: {0}")]

instant-xml/tests/all.rs

@@ -2,8 +2,6 @@ use std::borrow::Cow;
 
 use instant_xml::{Error, FromXml, ToXml};
 
-//TODO: Add compile time errors check?
-
 #[derive(Debug, Eq, PartialEq, ToXml)]
 struct Unit;
 
@@ -381,7 +379,14 @@ fn direct_namespaces() {
     );
 }
 
-#[derive(Debug, PartialEq, ToXml)]
+#[derive(Debug, PartialEq, Eq, FromXml, ToXml)]
+#[xml(namespace("URI"))]
+struct NestedLifetimes<'a> {
+    flag: bool,
+    str_type_a: &'a str,
+}
+
+#[derive(Debug, PartialEq, FromXml, ToXml)]
 #[xml(namespace("URI"))]
 struct StructDeserializerScalars<'a, 'b> {
     bool_type: bool,
@@ -392,14 +397,18 @@ struct StructDeserializerScalars<'a, 'b> {
     str_type_b: &'b str,
     char_type: char,
     f32_type: f32,
+    nested: NestedLifetimes<'a>,
     cow: Cow<'a, str>,
     option: Option<&'a str>,
 }
 
 #[test]
 fn scalars() {
-    // Option some
     assert_eq!(
+        StructDeserializerScalars::from_xml(
+            "<StructDeserializerScalars xmlns=\"URI\"><bool_type>true</bool_type><i8_type>1</i8_type><u32_type>42</u32_type><string_type>string</string_type><str_type_a>lifetime a</str_type_a><str_type_b>lifetime b</str_type_b><char_type>c</char_type><f32_type>1.20</f32_type><NestedLifetimes><flag>true</flag><str_type_a>asd</str_type_a></NestedLifetimes><cow>123</cow></StructDeserializerScalars>"
+        )
+        .unwrap(),
         StructDeserializerScalars{
             bool_type: true,
             i8_type: 1,
@@ -409,16 +418,20 @@ fn scalars() {
             str_type_b: "lifetime b",
             char_type: 'c',
             f32_type: 1.20,
+            nested: NestedLifetimes {
+                flag: true,
+                str_type_a: "asd"
+            },
             cow: Cow::from("123"),
-            option: Some("asd"),
+            option: None,
         }
-        .to_xml()
-        .unwrap(),
-        "<StructDeserializerScalars xmlns=\"URI\"><bool_type>true</bool_type><i8_type>1</i8_type><u32_type>42</u32_type><string_type>string</string_type><str_type_a>lifetime a</str_type_a><str_type_b>lifetime b</str_type_b><char_type>c</char_type><f32_type>1.2</f32_type><cow>123</cow><option>asd</option></StructDeserializerScalars>"
     );
 
     // Option none
     assert_eq!(
+        StructDeserializerScalars::from_xml(
+            "<StructDeserializerScalars xmlns=\"URI\"><bool_type>true</bool_type><i8_type>1</i8_type><u32_type>42</u32_type><string_type>string</string_type><str_type_a>lifetime a</str_type_a><str_type_b>lifetime b</str_type_b><char_type>c</char_type><f32_type>1.2</f32_type><NestedLifetimes><flag>true</flag><str_type_a>asd</str_type_a></NestedLifetimes><cow>123</cow><option>asd</option></StructDeserializerScalars>"
+        ).unwrap(),
         StructDeserializerScalars{
             bool_type: true,
             i8_type: 1,
@@ -428,33 +441,78 @@ fn scalars() {
             str_type_b: "lifetime b",
             char_type: 'c',
             f32_type: 1.20,
+            nested: NestedLifetimes {
+                flag: true,
+                str_type_a: "asd"
+            },
             cow: Cow::from("123"),
-            option: None,
+            option: Some("asd"),
         }
-        .to_xml()
-        .unwrap(),
-        "<StructDeserializerScalars xmlns=\"URI\"><bool_type>true</bool_type><i8_type>1</i8_type><u32_type>42</u32_type><string_type>string</string_type><str_type_a>lifetime a</str_type_a><str_type_b>lifetime b</str_type_b><char_type>c</char_type><f32_type>1.2</f32_type><cow>123</cow></StructDeserializerScalars>"
     );
 }
 
-#[derive(Debug, PartialEq, Eq, ToXml)]
+#[derive(Debug, PartialEq, Eq, FromXml, ToXml)]
 #[xml(namespace("URI"))]
 struct StructSpecialEntities<'a> {
-    string_type: String,
-    str_type_a: &'a str,
+    string: String,
+    str: &'a str,
     cow: Cow<'a, str>,
 }
 
+#[test]
+fn escape_back() {
+    assert_eq!(
+        StructSpecialEntities::from_xml(
+            "<StructSpecialEntities xmlns=\"URI\"><string>&lt;&gt;&amp;&quot;&apos;adsad&quot;</string><str>str</str><cow>str&amp;</cow></StructSpecialEntities>"
+        )
+        .unwrap(),
+        StructSpecialEntities {
+            string: String::from("<>&\"'adsad\""),
+            str: "str",
+            cow: Cow::Owned("str&".to_string()),
+        }
+    );
+
+    // Wrong str char
+    assert_eq!(
+        StructSpecialEntities::from_xml(
+            "<StructSpecialEntities xmlns=\"URI\"><string>&lt;&gt;&amp;&quot;&apos;adsad&quot;</string><str>str&amp;</str></StructSpecialEntities>"
+        )
+        .unwrap_err(),
+        Error::Other("Unsupported char: str&".to_string())
+    );
+
+    // Borrowed
+    let escape_back = StructSpecialEntities::from_xml(
+        "<StructSpecialEntities xmlns=\"URI\"><string>&lt;&gt;&amp;&quot;&apos;adsad&quot;</string><str>str</str><cow>str</cow></StructSpecialEntities>"
+    )
+    .unwrap();
+
+    if let Cow::Owned(_) = escape_back.cow {
+        panic!("Should be Borrowed")
+    }
+
+    // Owned
+    let escape_back = StructSpecialEntities::from_xml(
+            "<StructSpecialEntities xmlns=\"URI\"><string>&lt;&gt;&amp;&quot;&apos;adsad&quot;</string><str>str</str><cow>str&amp;</cow></StructSpecialEntities>"
+        )
+        .unwrap();
+
+    if let Cow::Borrowed(_) = escape_back.cow {
+        panic!("Should be Owned")
+    }
+}
+
 #[test]
 fn special_entities() {
     assert_eq!(
         StructSpecialEntities{
-            string_type: "&\"<>\'aa".to_string(),
-            str_type_a: "&\"<>\'bb",
+            string: "&\"<>\'aa".to_string(),
+            str: "&\"<>\'bb",
             cow: Cow::from("&\"<>\'cc"),
         }
         .to_xml()
         .unwrap(),
-        "<StructSpecialEntities xmlns=\"URI\"><string_type>&amp;&quot;&lt;&gt;&apos;aa</string_type><str_type_a>&amp;&quot;&lt;&gt;&apos;bb</str_type_a><cow>&amp;&quot;&lt;&gt;&apos;cc</cow></StructSpecialEntities>"
+        "<StructSpecialEntities xmlns=\"URI\"><string>&amp;&quot;&lt;&gt;&apos;aa</string><str>&amp;&quot;&lt;&gt;&apos;bb</str><cow>&amp;&quot;&lt;&gt;&apos;cc</cow></StructSpecialEntities>"
     );
 }