diff --git a/src/font.rs b/src/font.rs
index 6ed6316..60d69e6 100644
--- a/src/font.rs
+++ b/src/font.rs
@@ -304,26 +304,26 @@ pub fn debug_font_names(font: &CTFont) {
         get_string_by_name_key(font, key).unwrap()
     }
 
-    println!("kCTFontFamilyNameKey: {:s}", get_key(font, kCTFontFamilyNameKey));
-    println!("kCTFontSubFamilyNameKey: {:s}", get_key(font, kCTFontSubFamilyNameKey));
-    println!("kCTFontStyleNameKey: {:s}", get_key(font, kCTFontStyleNameKey));
-    println!("kCTFontUniqueNameKey: {:s}", get_key(font, kCTFontUniqueNameKey));
-    println!("kCTFontFullNameKey: {:s}", get_key(font, kCTFontFullNameKey));
-    println!("kCTFontPostScriptNameKey: {:s}", get_key(font, kCTFontPostScriptNameKey));
+    println!("kCTFontFamilyNameKey: {}", get_key(font, kCTFontFamilyNameKey));
+    println!("kCTFontSubFamilyNameKey: {}", get_key(font, kCTFontSubFamilyNameKey));
+    println!("kCTFontStyleNameKey: {}", get_key(font, kCTFontStyleNameKey));
+    println!("kCTFontUniqueNameKey: {}", get_key(font, kCTFontUniqueNameKey));
+    println!("kCTFontFullNameKey: {}", get_key(font, kCTFontFullNameKey));
+    println!("kCTFontPostScriptNameKey: {}", get_key(font, kCTFontPostScriptNameKey));
 }
 
 pub fn debug_font_traits(font: &CTFont) {
     let sym = font.symbolic_traits();
-    println!("kCTFontItalicTrait: {:b}", sym.is_italic());
-    println!("kCTFontBoldTrait: {:b}", sym.is_bold());
-    println!("kCTFontExpandedTrait: {:b}", sym.is_expanded());
-    println!("kCTFontCondensedTrait: {:b}", sym.is_condensed());
-    println!("kCTFontMonoSpaceTrait: {:b}", sym.is_monospace());
+    println!("kCTFontItalicTrait: {}", sym.is_italic());
+    println!("kCTFontBoldTrait: {}", sym.is_bold());
+    println!("kCTFontExpandedTrait: {}", sym.is_expanded());
+    println!("kCTFontCondensedTrait: {}", sym.is_condensed());
+    println!("kCTFontMonoSpaceTrait: {}", sym.is_monospace());
 
     let traits = font.all_traits();
-    println!("kCTFontWeightTrait: {:f}", traits.normalized_weight());
-//    println!("kCTFontWidthTrait: {:f}", traits.normalized_width());
-//    println!("kCTFontSlantTrait: {:f}", traits.normalized_slant());
+    println!("kCTFontWeightTrait: {}", traits.normalized_weight());
+//    println!("kCTFontWidthTrait: {}", traits.normalized_width());
+//    println!("kCTFontSlantTrait: {}", traits.normalized_slant());
 }
 
 #[link(name = "ApplicationServices", kind = "framework")]
diff --git a/src/font_collection.rs b/src/font_collection.rs
index 61d35f3..d594d19 100644
--- a/src/font_collection.rs
+++ b/src/font_collection.rs
@@ -86,7 +86,7 @@ pub fn new_from_descriptors(descs: &CFArray) -> CTFontCollection {
     unsafe {
         let key: CFString = TCFType::wrap_under_get_rule(kCTFontCollectionRemoveDuplicatesOption);
         let value: CFNumber = FromPrimitive::from_i8(1).unwrap();
-        let options = CFDictionary::from_CFType_pairs([ (key.as_CFType(), value.as_CFType()) ]);
+        let options = CFDictionary::from_CFType_pairs(&[ (key.as_CFType(), value.as_CFType()) ]);
         let font_collection_ref =
             CTFontCollectionCreateWithFontDescriptors(descs.as_concrete_TypeRef(),
                                                       options.as_concrete_TypeRef());
@@ -98,7 +98,7 @@ pub fn create_for_all_families() -> CTFontCollection {
     unsafe {
         let key: CFString = TCFType::wrap_under_get_rule(kCTFontCollectionRemoveDuplicatesOption);
         let value: CFNumber = FromPrimitive::from_i8(1).unwrap();
-        let options = CFDictionary::from_CFType_pairs([ (key.as_CFType(), value.as_CFType()) ]);
+        let options = CFDictionary::from_CFType_pairs(&[ (key.as_CFType(), value.as_CFType()) ]);
         let font_collection_ref =
             CTFontCollectionCreateFromAvailableFonts(options.as_concrete_TypeRef());
         TCFType::wrap_under_create_rule(font_collection_ref)
@@ -111,13 +111,13 @@ pub fn create_for_family(family: &str) -> Option<CTFontCollection> {
     unsafe {
         let family_attr: CFString = TCFType::wrap_under_get_rule(kCTFontFamilyNameAttribute);
         let family_name: CFString = from_str(family).unwrap();
-        let specified_attrs = CFDictionary::from_CFType_pairs([
+        let specified_attrs = CFDictionary::from_CFType_pairs(&[
             (family_attr.as_CFType(), family_name.as_CFType())
         ]);
 
         let wildcard_desc: CTFontDescriptor =
             font_descriptor::new_from_attributes(&specified_attrs);
-        let mandatory_attrs = CFSet::from_slice([ family_attr.as_CFType() ]);
+        let mandatory_attrs = CFSet::from_slice(&[ family_attr.as_CFType() ]);
         let matched_descs = CTFontDescriptorCreateMatchingFontDescriptors(
                 wildcard_desc.as_concrete_TypeRef(),
                 mandatory_attrs.as_concrete_TypeRef());
diff --git a/src/font_descriptor.rs b/src/font_descriptor.rs
index ddbd44e..60a3520 100644
--- a/src/font_descriptor.rs
+++ b/src/font_descriptor.rs
@@ -291,11 +291,11 @@ pub fn new_from_attributes(attributes: &CFDictionary) -> CTFontDescriptor {
 }
 
 pub fn debug_descriptor(desc: &CTFontDescriptor) {
-    println!("family: {:s}", desc.family_name());
-    println!("name: {:s}", desc.font_name());
-    println!("style: {:s}", desc.style_name());
-    println!("display: {:s}", desc.display_name());
-    println!("path: {:s}", desc.font_path());
+    println!("family: {}", desc.family_name());
+    println!("name: {}", desc.font_name());
+    println!("style: {}", desc.style_name());
+    println!("display: {}", desc.display_name());
+    println!("path: {}", desc.font_path());
     desc.show();
 }