diff --git a/gsl/gsl_byte b/gsl/gsl_byte
index bee1092..ab5e4e3 100644
--- a/gsl/gsl_byte
+++ b/gsl/gsl_byte
@@ -26,7 +26,7 @@
 
 // constexpr is not understood
 #pragma push_macro("constexpr")
-#define constexpr /*constexpr*/ 
+#define constexpr /*constexpr*/
 
 // noexcept is not understood
 #pragma push_macro("noexcept")
@@ -45,25 +45,25 @@ enum class byte : unsigned char
 };
 
 template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
-constexpr byte& operator<<=(byte& b, IntegerType shift) noexcept
+inline constexpr byte& operator<<=(byte& b, IntegerType shift) noexcept
 {
     return b = byte(static_cast<unsigned char>(b) << shift);
 }
 
 template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
-constexpr byte operator<<(byte b, IntegerType shift) noexcept
+inline constexpr byte operator<<(byte b, IntegerType shift) noexcept
 {
     return byte(static_cast<unsigned char>(b) << shift);
 }
 
 template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
-constexpr byte& operator>>=(byte& b, IntegerType shift) noexcept
+inline constexpr byte& operator>>=(byte& b, IntegerType shift) noexcept
 {
     return b = byte(static_cast<unsigned char>(b) >> shift);
 }
 
 template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
-constexpr byte operator>>(byte b, IntegerType shift) noexcept
+inline constexpr byte operator>>(byte b, IntegerType shift) noexcept
 {
     return byte(static_cast<unsigned char>(b) >> shift);
 }
@@ -101,13 +101,13 @@ inline constexpr byte operator^(byte l, byte r) noexcept
 inline constexpr byte operator~(byte b) noexcept { return byte(~static_cast<unsigned char>(b)); }
 
 template <class IntegerType, class = std::enable_if_t<std::is_integral<IntegerType>::value>>
-constexpr IntegerType to_integer(byte b) noexcept
+inline constexpr IntegerType to_integer(byte b) noexcept
 {
     return {b};
 }
 
 template<bool E, typename T>
-constexpr byte to_byte_impl(T t) noexcept
+inline constexpr byte to_byte_impl(T t) noexcept
 {
     static_assert(
         E,
@@ -117,19 +117,19 @@ constexpr byte to_byte_impl(T t) noexcept
     return static_cast<byte>(t);
 }
 template<>
-constexpr byte to_byte_impl<true, unsigned char>(unsigned char t) noexcept
+inline constexpr byte to_byte_impl<true, unsigned char>(unsigned char t) noexcept
 {
      return byte(t);
 }
 
 template<typename T>
-constexpr byte to_byte(T t) noexcept
+inline constexpr byte to_byte(T t) noexcept
 {
      return to_byte_impl<std::is_same<T, unsigned char>::value, T>(t);
 }
 
 template <int I>
-constexpr byte to_byte() noexcept
+inline constexpr byte to_byte() noexcept
 {
     static_assert(I >= 0 && I <= 255, "gsl::byte only has 8 bits of storage, values must be in range 0-255");
     return static_cast<byte>(I);