Add typedefs and deprecation warnings

Author: mborland

include/boost/decimal/decimal128.hpp

@@ -89,6 +89,7 @@ BOOST_DECIMAL_CONSTEXPR_VARIABLE int128::uint128_t d128_max_significand_value {U
 
 } //namespace detail
 
+[[deprecated("Use re-named type decimal128_t instead of decimal128")]]
 BOOST_DECIMAL_EXPORT class decimal128 final
 {
 public:
@@ -543,6 +544,8 @@ BOOST_DECIMAL_EXPORT class decimal128 final
     friend constexpr auto fmad128(decimal128 x, decimal128 y, decimal128 z) noexcept -> decimal128;
 };
 
+using decimal128_t = decimal128;
+
 #if !defined(BOOST_DECIMAL_DISABLE_IOSTREAM)
 inline std::string bit_string(decimal128 rhs) noexcept
 {

include/boost/decimal/decimal128_fast.hpp

@@ -40,6 +40,7 @@ BOOST_DECIMAL_CONSTEXPR_VARIABLE auto d128_fast_snan_high_bits = UINT64_MAX;
 
 } // namespace detail
 
+[[deprecated("Use re-named type decimal_fast128_t instead of decimal128_fast")]]
 BOOST_DECIMAL_EXPORT class decimal128_fast final
 {
 public:
@@ -369,6 +370,8 @@ BOOST_DECIMAL_EXPORT class decimal128_fast final
     friend constexpr auto quantized128f(const decimal128_fast& lhs, const decimal128_fast& rhs) noexcept -> decimal128_fast;
 };
 
+using decimal_fast128_t = decimal128_fast;
+
 #ifdef BOOST_DECIMAL_HAS_CONCEPTS
 template <BOOST_DECIMAL_UNSIGNED_INTEGRAL T1, BOOST_DECIMAL_INTEGRAL T2>
 #else

include/boost/decimal/decimal32.hpp

@@ -101,6 +101,7 @@ BOOST_DECIMAL_CONSTEXPR_VARIABLE std::uint32_t d32_max_significand_value = UINT3
 
 // ISO/IEC DTR 24733
 // 3.2.2 class decimal32
+[[deprecated("Use re-named type decimal32_t instead of decimal32")]]
 BOOST_DECIMAL_EXPORT class decimal32 final // NOLINT(cppcoreguidelines-special-member-functions,hicpp-special-member-functions)
 {
 public:
@@ -563,6 +564,8 @@ BOOST_DECIMAL_EXPORT class decimal32 final // NOLINT(cppcoreguidelines-special-m
     constexpr auto edit_sign(bool sign) noexcept -> void;
 };
 
+BOOST_DECIMAL_EXPORT using decimal32_t = decimal32;
+
 #if defined(__GNUC__) && __GNUC__ >= 8
 #  pragma GCC diagnostic pop
 #endif

include/boost/decimal/decimal32_fast.hpp

@@ -35,6 +35,7 @@ BOOST_DECIMAL_CONSTEXPR_VARIABLE auto d32_fast_snan = std::numeric_limits<std::u
 
 }
 
+[[deprecated("Use re-named type decimal_fast32_t instead of decimal32_fast")]]
 BOOST_DECIMAL_EXPORT class decimal32_fast final
 {
 public:
@@ -374,6 +375,8 @@ BOOST_DECIMAL_EXPORT class decimal32_fast final
     friend constexpr auto quantized32f(decimal32_fast lhs, decimal32_fast rhs) noexcept -> decimal32_fast;
 };
 
+BOOST_DECIMAL_EXPORT using decimal_fast32_t = decimal32_fast;
+
 template <typename T1, typename T2, std::enable_if_t<detail::is_unsigned_v<T1> && detail::is_integral_v<T2>, bool>>
 constexpr decimal32_fast::decimal32_fast(T1 coeff, T2 exp, bool sign) noexcept
 {

include/boost/decimal/decimal64.hpp

@@ -96,6 +96,7 @@ BOOST_DECIMAL_CONSTEXPR_VARIABLE std::uint64_t d64_max_significand_value = UINT6
 #  pragma GCC diagnostic ignored "-Wclass-memaccess"
 #endif
 
+[[deprecated("Use re-named type decimal64_t instead of decimal64")]]
 BOOST_DECIMAL_EXPORT class decimal64 final
 {
 public:
@@ -551,6 +552,8 @@ BOOST_DECIMAL_EXPORT class decimal64 final
     friend constexpr auto scalblnd64(decimal64 num, long exp) noexcept -> decimal64;
 };
 
+using decimal64_t = decimal64;
+
 #if defined(__GNUC__) && __GNUC__ >= 8
 #  pragma GCC diagnostic pop
 #endif

include/boost/decimal/decimal64_fast.hpp

@@ -48,6 +48,7 @@ struct decimal64_fast_components
 
 } // namespace detail
 
+[[deprecated("Use re-named type decimal_fast64_t instead of decimal64_fast")]]
 BOOST_DECIMAL_EXPORT class decimal64_fast final
 {
 public:
@@ -382,6 +383,8 @@ BOOST_DECIMAL_EXPORT class decimal64_fast final
     friend constexpr auto scalblnd64f(decimal64_fast num, long exp) noexcept -> decimal64_fast;
 };
 
+using decimal_fast64_t = decimal64_fast;
+
 #ifdef BOOST_DECIMAL_HAS_CONCEPTS
 template <BOOST_DECIMAL_UNSIGNED_INTEGRAL T1, BOOST_DECIMAL_INTEGRAL T2>
 #else