diff --git a/src/catch2/catch_tostring.cpp b/src/catch2/catch_tostring.cpp
index 3a63a598..4eeabbae 100644
--- a/src/catch2/catch_tostring.cpp
+++ b/src/catch2/catch_tostring.cpp
@@ -201,11 +201,6 @@ std::string StringMaker<unsigned long long>::convert(unsigned long long value) {
     return rss.str();
 }
 
-
-std::string StringMaker<bool>::convert(bool b) {
-    return b ? "true" : "false";
-}
-
 std::string StringMaker<signed char>::convert(signed char value) {
     if (value == '\r') {
         return "'\\r'";
@@ -230,10 +225,6 @@ std::string StringMaker<unsigned char>::convert(unsigned char c) {
     return ::Catch::Detail::stringify(static_cast<char>(c));
 }
 
-std::string StringMaker<std::nullptr_t>::convert(std::nullptr_t) {
-    return "nullptr";
-}
-
 int StringMaker<float>::precision = 5;
 
 std::string StringMaker<float>::convert(float value) {
diff --git a/src/catch2/catch_tostring.hpp b/src/catch2/catch_tostring.hpp
index 77f05fe0..04cd84df 100644
--- a/src/catch2/catch_tostring.hpp
+++ b/src/catch2/catch_tostring.hpp
@@ -239,7 +239,10 @@ namespace Catch {
 
     template<>
     struct StringMaker<bool> {
-        static std::string convert(bool b);
+        static std::string convert(bool b) {
+            using namespace std::string_literals;
+            return b ? "true"s : "false"s;
+        }
     };
 
     template<>
@@ -257,7 +260,10 @@ namespace Catch {
 
     template<>
     struct StringMaker<std::nullptr_t> {
-        static std::string convert(std::nullptr_t);
+        static std::string convert(std::nullptr_t) {
+            using namespace std::string_literals;
+            return "nullptr"s;
+        }
     };
 
     template<>
@@ -512,18 +518,14 @@ namespace Catch {
 
 template <class Ratio>
 struct ratio_string {
-    static std::string symbol();
+    static std::string symbol() {
+        Catch::ReusableStringStream rss;
+        rss << '[' << Ratio::num << '/'
+            << Ratio::den << ']';
+        return rss.str();
+    }
 };
 
-template <class Ratio>
-std::string ratio_string<Ratio>::symbol() {
-    Catch::ReusableStringStream rss;
-    rss << '[' << Ratio::num << '/'
-        << Ratio::den << ']';
-    return rss.str();
-}
-
-
 template <>
 struct ratio_string<std::atto> {
     static std::string symbol() { return "a"; }