diff --git a/include/CppCore.Test/Encoding.h b/include/CppCore.Test/Encoding.h
index eb1df186..a1eb6853 100644
--- a/include/CppCore.Test/Encoding.h
+++ b/include/CppCore.Test/Encoding.h
@@ -141,6 +141,141 @@ namespace CppCore { namespace Test
             // TODO: More than Base10
             return true;
          }
+         INLINE static bool parse8()
+         {
+            uint8_t r;
+            CppCore::BaseX::parse("",    r, CPPCORE_ALPHABET_B10); if (r != 0) return false;
+            CppCore::BaseX::parse("0",   r, CPPCORE_ALPHABET_B10); if (r != 0) return false;
+            CppCore::BaseX::parse("1",   r, CPPCORE_ALPHABET_B10); if (r != 1) return false;
+            CppCore::BaseX::parse("143", r, CPPCORE_ALPHABET_B10); if (r != 143) return false;
+            CppCore::BaseX::parse("255", r, CPPCORE_ALPHABET_B10); if (r != 255) return false;
+            CppCore::BaseX::parse("256", r, CPPCORE_ALPHABET_B10); if (r != 0) return false;
+            return true;
+         }
+         INLINE static bool parse16()
+         {
+            uint16_t r;
+            CppCore::BaseX::parse("",      r, CPPCORE_ALPHABET_B10); if (r != 0) return false;
+            CppCore::BaseX::parse("0",     r, CPPCORE_ALPHABET_B10); if (r != 0) return false;
+            CppCore::BaseX::parse("1",     r, CPPCORE_ALPHABET_B10); if (r != 1) return false;
+            CppCore::BaseX::parse("143",   r, CPPCORE_ALPHABET_B10); if (r != 143) return false;
+            CppCore::BaseX::parse("255",   r, CPPCORE_ALPHABET_B10); if (r != 255) return false;
+            CppCore::BaseX::parse("65535", r, CPPCORE_ALPHABET_B10); if (r != 65535) return false;
+            CppCore::BaseX::parse("65536", r, CPPCORE_ALPHABET_B10); if (r != 0) return false;
+            return true;
+         }
+         INLINE static bool parse32()
+         {
+            uint32_t r;
+            CppCore::BaseX::parse("",           r, CPPCORE_ALPHABET_B10); if (r != 0U) return false;
+            CppCore::BaseX::parse("0",          r, CPPCORE_ALPHABET_B10); if (r != 0U) return false;
+            CppCore::BaseX::parse("1",          r, CPPCORE_ALPHABET_B10); if (r != 1U) return false;
+            CppCore::BaseX::parse("143",        r, CPPCORE_ALPHABET_B10); if (r != 143U) return false;
+            CppCore::BaseX::parse("255",        r, CPPCORE_ALPHABET_B10); if (r != 255U) return false;
+            CppCore::BaseX::parse("65535",      r, CPPCORE_ALPHABET_B10); if (r != 65535U) return false;
+            CppCore::BaseX::parse("4294967295", r, CPPCORE_ALPHABET_B10); if (r != 4294967295U) return false;
+            CppCore::BaseX::parse("4294967296", r, CPPCORE_ALPHABET_B10); if (r != 0) return false;
+            return true;
+         }
+         INLINE static bool parse64()
+         {
+            uint64_t r;
+            CppCore::BaseX::parse("",           r, CPPCORE_ALPHABET_B10); if (r != 0U) return false;
+            CppCore::BaseX::parse("0",          r, CPPCORE_ALPHABET_B10); if (r != 0U) return false;
+            CppCore::BaseX::parse("1",          r, CPPCORE_ALPHABET_B10); if (r != 1U) return false;
+            CppCore::BaseX::parse("143",        r, CPPCORE_ALPHABET_B10); if (r != 143U) return false;
+            CppCore::BaseX::parse("255",        r, CPPCORE_ALPHABET_B10); if (r != 255U) return false;
+            CppCore::BaseX::parse("65535",      r, CPPCORE_ALPHABET_B10); if (r != 65535U) return false;
+            CppCore::BaseX::parse("4294967295", r, CPPCORE_ALPHABET_B10); if (r != 4294967295U) return false;
+            CppCore::BaseX::parse("18446744073709551615", r, CPPCORE_ALPHABET_B10); if (r != 18446744073709551615ULL) return false;
+            CppCore::BaseX::parse("18446744073709551616", r, CPPCORE_ALPHABET_B10); if (r != 0) return false;
+            return true;
+         }
+         INLINE static bool parse128()
+         {
+            uint64_t r[2];
+            CppCore::BaseX::parse("",           r, CPPCORE_ALPHABET_B10); if (r[1] != 0U || r[0] != 0U) return false;
+            CppCore::BaseX::parse("0",          r, CPPCORE_ALPHABET_B10); if (r[1] != 0U || r[0] != 0U) return false;
+            CppCore::BaseX::parse("1",          r, CPPCORE_ALPHABET_B10); if (r[1] != 0U || r[0] != 1U) return false;
+            CppCore::BaseX::parse("143",        r, CPPCORE_ALPHABET_B10); if (r[1] != 0U || r[0] != 143U) return false;
+            CppCore::BaseX::parse("255",        r, CPPCORE_ALPHABET_B10); if (r[1] != 0U || r[0] != 255U) return false;
+            CppCore::BaseX::parse("65535",      r, CPPCORE_ALPHABET_B10); if (r[1] != 0U || r[0] != 65535U) return false;
+            CppCore::BaseX::parse("4294967295", r, CPPCORE_ALPHABET_B10); if (r[1] != 0U || r[0] != 4294967295U) return false;
+            CppCore::BaseX::parse("18446744073709551615", r, CPPCORE_ALPHABET_B10); if (r[1] != 0U || r[0] != 18446744073709551615ULL) return false;
+            CppCore::BaseX::parse("340282366920938463463374607431768211455", r, CPPCORE_ALPHABET_B10); if (r[1] != 0xFFFFFFFFFFFFFFFFULL || r[0] != 0xFFFFFFFFFFFFFFFFULL) return false;
+            CppCore::BaseX::parse("340282366920938463463374607431768211456", r, CPPCORE_ALPHABET_B10); if (r[1] != 0U || r[0] != 0U) return false;
+            return true;
+         }
+         INLINE static bool tryparse8()
+         {
+            uint8_t r;
+            if (!CppCore::BaseX::tryparse("0",   r, CPPCORE_ALPHABET_B10) || r != 0) return false;
+            if (!CppCore::BaseX::tryparse("1",   r, CPPCORE_ALPHABET_B10) || r != 1) return false;
+            if (!CppCore::BaseX::tryparse("143", r, CPPCORE_ALPHABET_B10) || r != 143) return false;
+            if (!CppCore::BaseX::tryparse("255", r, CPPCORE_ALPHABET_B10) || r != 255) return false;
+            if ( CppCore::BaseX::tryparse("256", r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("",    r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("x",   r, CPPCORE_ALPHABET_B10)) return false;
+            return true;
+         }
+         INLINE static bool tryparse16()
+         {
+            uint16_t r;
+            if (!CppCore::BaseX::tryparse("0",     r, CPPCORE_ALPHABET_B10) || r != 0) return false;
+            if (!CppCore::BaseX::tryparse("1",     r, CPPCORE_ALPHABET_B10) || r != 1) return false;
+            if (!CppCore::BaseX::tryparse("143",   r, CPPCORE_ALPHABET_B10) || r != 143) return false;
+            if (!CppCore::BaseX::tryparse("255",   r, CPPCORE_ALPHABET_B10) || r != 255) return false;
+            if (!CppCore::BaseX::tryparse("65535", r, CPPCORE_ALPHABET_B10) || r != 65535) return false;
+            if ( CppCore::BaseX::tryparse("65536", r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("",      r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("x",     r, CPPCORE_ALPHABET_B10)) return false;
+            return true;
+         }
+         INLINE static bool tryparse32()
+         {
+            uint32_t r;
+            if (!CppCore::BaseX::tryparse("0",     r, CPPCORE_ALPHABET_B10) || r != 0) return false;
+            if (!CppCore::BaseX::tryparse("1",     r, CPPCORE_ALPHABET_B10) || r != 1) return false;
+            if (!CppCore::BaseX::tryparse("143",   r, CPPCORE_ALPHABET_B10) || r != 143) return false;
+            if (!CppCore::BaseX::tryparse("255",   r, CPPCORE_ALPHABET_B10) || r != 255) return false;
+            if (!CppCore::BaseX::tryparse("65535", r, CPPCORE_ALPHABET_B10) || r != 65535) return false;
+            if (!CppCore::BaseX::tryparse("4294967295", r, CPPCORE_ALPHABET_B10) || r != 4294967295U) return false;
+            if ( CppCore::BaseX::tryparse("4294967296", r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("",      r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("x",     r, CPPCORE_ALPHABET_B10)) return false;
+            return true;
+         }
+         INLINE static bool tryparse64()
+         {
+            uint64_t r;
+            if (!CppCore::BaseX::tryparse("0",     r, CPPCORE_ALPHABET_B10) || r != 0) return false;
+            if (!CppCore::BaseX::tryparse("1",     r, CPPCORE_ALPHABET_B10) || r != 1) return false;
+            if (!CppCore::BaseX::tryparse("143",   r, CPPCORE_ALPHABET_B10) || r != 143) return false;
+            if (!CppCore::BaseX::tryparse("255",   r, CPPCORE_ALPHABET_B10) || r != 255) return false;
+            if (!CppCore::BaseX::tryparse("65535", r, CPPCORE_ALPHABET_B10) || r != 65535) return false;
+            if (!CppCore::BaseX::tryparse("4294967295", r, CPPCORE_ALPHABET_B10) || r != 4294967295U) return false;
+            if (!CppCore::BaseX::tryparse("18446744073709551615", r, CPPCORE_ALPHABET_B10) || r != 18446744073709551615ULL) return false;
+            if ( CppCore::BaseX::tryparse("18446744073709551616", r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("",      r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("x",     r, CPPCORE_ALPHABET_B10)) return false;
+            return true;
+         }
+         INLINE static bool tryparse128()
+         {
+            uint64_t r[2];
+            if (!CppCore::BaseX::tryparse("0",          r, CPPCORE_ALPHABET_B10) || r[1] != 0U || r[0] != 0U) return false;
+            if (!CppCore::BaseX::tryparse("1",          r, CPPCORE_ALPHABET_B10) || r[1] != 0U || r[0] != 1U) return false;
+            if (!CppCore::BaseX::tryparse("143",        r, CPPCORE_ALPHABET_B10) || r[1] != 0U || r[0] != 143U) return false;
+            if (!CppCore::BaseX::tryparse("255",        r, CPPCORE_ALPHABET_B10) || r[1] != 0U || r[0] != 255U) return false;
+            if (!CppCore::BaseX::tryparse("65535",      r, CPPCORE_ALPHABET_B10) || r[1] != 0U || r[0] != 65535U) return false;
+            if (!CppCore::BaseX::tryparse("4294967295", r, CPPCORE_ALPHABET_B10) || r[1] != 0U || r[0] != 4294967295U) return false;
+            if (!CppCore::BaseX::tryparse("18446744073709551615", r, CPPCORE_ALPHABET_B10) || r[1] != 0U || r[0] != 18446744073709551615ULL) return false;
+            if (!CppCore::BaseX::tryparse("340282366920938463463374607431768211455", r, CPPCORE_ALPHABET_B10) || r[1] != 0xFFFFFFFFFFFFFFFFULL || r[0] != 0xFFFFFFFFFFFFFFFFULL) return false;
+            if ( CppCore::BaseX::tryparse("340282366920938463463374607431768211456", r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("",      r, CPPCORE_ALPHABET_B10)) return false;
+            if ( CppCore::BaseX::tryparse("x",     r, CPPCORE_ALPHABET_B10)) return false;
+            return true;
+         }
       };
       class Hex
       {
@@ -910,6 +1045,16 @@ namespace CppCore { namespace Test { namespace VS
       TEST_METHOD(BASEX_TOSTRING16) { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::tostring16()); }
       TEST_METHOD(BASEX_TOSTRING32) { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::tostring32()); }
       TEST_METHOD(BASEX_TOSTRING64) { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::tostring64()); }
+      TEST_METHOD(BASEX_PARSE8)     { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::parse8()); }
+      TEST_METHOD(BASEX_PARSE16)    { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::parse16()); }
+      TEST_METHOD(BASEX_PARSE32)    { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::parse32()); }
+      TEST_METHOD(BASEX_PARSE64)    { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::parse64()); }
+      TEST_METHOD(BASEX_PARSE128)   { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::parse128()); }
+      TEST_METHOD(BASEX_TRYPARSE8)  { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::tryparse8()); }
+      TEST_METHOD(BASEX_TRYPARSE16) { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::tryparse16()); }
+      TEST_METHOD(BASEX_TRYPARSE32) { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::tryparse32()); }
+      TEST_METHOD(BASEX_TRYPARSE64) { Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::tryparse64()); }
+      TEST_METHOD(BASEX_TRYPARSE128){ Assert::AreEqual(true, CppCore::Test::Encoding::BaseX::tryparse128()); }
       TEST_METHOD(HEX_BYTETOHEXSTR) { Assert::AreEqual(true, CppCore::Test::Encoding::Hex::Util::bytetohexstr()); }
       TEST_METHOD(HEX_TOSTRING)     { Assert::AreEqual(true, CppCore::Test::Encoding::Hex::tostring()); }
       TEST_METHOD(HEX_TOSTRING16)   { Assert::AreEqual(true, CppCore::Test::Encoding::Hex::tostring16()); }
diff --git a/include/CppCore/Encoding.h b/include/CppCore/Encoding.h
index 384d4639..f11eeeb3 100644
--- a/include/CppCore/Encoding.h
+++ b/include/CppCore/Encoding.h
@@ -213,18 +213,18 @@ namespace CppCore
       {
          assert(::strlen(alphabet) >= 2);
          uint8_t tbl[256];
-         size_t n = 0;
+         uint8_t n = 0;
          CppCore::clear(r);
          CppCore::clear(tbl);
          while (const char c = *alphabet++)
-            tbl[c] = (uint8_t)n++;
+            tbl[c] = n++;
          if (const char c = *input++)
          {
             *(uint8_t*)&r = tbl[c];
             while (const char c = *input++)
             {
                CppCore::umul(r, n, r);
-               CppCore::uadd(r, (size_t)tbl[c], r);
+               CppCore::uadd(r, tbl[c], r);
             }
          }
       }
@@ -239,10 +239,10 @@ namespace CppCore
          if (!input || !alphabet)
             return false; // null pointer
          uint8_t tbl[256];
-         size_t n = 0;
+         uint8_t n = 0;
          CppCore::bytedup(0xFF, tbl);
          while (const char c = *alphabet++)
-            tbl[c] = (uint8_t)n++;
+            tbl[c] = n++;
          if (n < 2U) CPPCORE_UNLIKELY
             return false; // alphabet too short
          if (const char first = *input++) CPPCORE_LIKELY
@@ -262,7 +262,7 @@ namespace CppCore
                if (t.of != 0U) CPPCORE_UNLIKELY
                   return false; // mul overflow
                uint8_t carry = 0;
-               CppCore::addcarry(t.v, (size_t)idx, r, carry);
+               CppCore::addcarry(t.v, idx, r, carry);
                if (carry != 0) CPPCORE_UNLIKELY
                   return false; // add overflow
             }
diff --git a/include/CppCore/Math/Util.h b/include/CppCore/Math/Util.h
index 61ffd4e6..aa9fa6f5 100644
--- a/include/CppCore/Math/Util.h
+++ b/include/CppCore/Math/Util.h
@@ -639,8 +639,8 @@ namespace CppCore
    template<typename UINT1, typename UINT2, typename UINT3>
    INLINE static void addcarry(const UINT1& x, const UINT2& y, UINT3& z, uint8_t& c)
    {
-      static_assert(sizeof(UINT1) % 4 == 0);
-      static_assert(sizeof(UINT2) % 4 == 0);
+      static_assert(sizeof(UINT1) % 4 == 0 || sizeof(UINT1) < sizeof(size_t));
+      static_assert(sizeof(UINT2) % 4 == 0 || sizeof(UINT2) < sizeof(size_t));
       static_assert(sizeof(UINT3) % 4 == 0);
       constexpr size_t MAXSIZE = MAX(sizeof(UINT1), sizeof(UINT2));
       constexpr size_t MINSIZE = MIN(sizeof(UINT1), sizeof(UINT2));
@@ -663,8 +663,11 @@ namespace CppCore
             for (size_t i = NMIN; i < NUINT2; i++)
                CppCore::addcarry64(0ULL, py[i], pz[i], c);
       }
-      else
+      else if
+   #else
+      if
    #endif
+         constexpr (sizeof(UINT1) % 4 == 0 && sizeof(UINT2) % 4 == 0 && sizeof(UINT3) % 4 == 0)
       {
          constexpr size_t NUINT1 = sizeof(UINT1) / 4;
          constexpr size_t NUINT2 = sizeof(UINT2) / 4;
@@ -681,6 +684,9 @@ namespace CppCore
             for (size_t i = NMIN; i < NUINT2; i++)
                CppCore::addcarry32(0U, py[i], pz[i], c);
       }
+      else if constexpr (sizeof(UINT1) < sizeof(size_t)) { addcarry<size_t, UINT2, UINT3>((size_t)x, y, z, c); }
+      else if constexpr (sizeof(UINT2) < sizeof(size_t)) { addcarry<UINT1, size_t, UINT3>(x, (size_t)y, z, c); }
+      else throw;
    }
 
    /// <summary>
@@ -691,6 +697,14 @@ namespace CppCore
       CppCore::addcarry8(x, y, r, c);
    }
 
+   /// <summary>
+   /// Template Specialization for 16+8=16
+   /// </summary>
+   template<> INLINE void addcarry(const uint16_t& x, const uint8_t& y, uint16_t& r, uint8_t& c)
+   {
+      CppCore::addcarry16(x, y, r, c);
+   }
+
    /// <summary>
    /// Template Specialization for 16+16=16
    /// </summary>
@@ -699,6 +713,22 @@ namespace CppCore
       CppCore::addcarry16(x, y, r, c);
    }
 
+   /// <summary>
+   /// Template Specialization for 32+8=32
+   /// </summary>
+   template<> INLINE void addcarry(const uint32_t& x, const uint8_t& y, uint32_t& r, uint8_t& c)
+   {
+      CppCore::addcarry32(x, y, r, c);
+   }
+
+   /// <summary>
+   /// Template Specialization for 32+16=32
+   /// </summary>
+   template<> INLINE void addcarry(const uint32_t& x, const uint16_t& y, uint32_t& r, uint8_t& c)
+   {
+      CppCore::addcarry32(x, y, r, c);
+   }
+
    /// <summary>
    /// Template Specialization for 32+32=32
    /// </summary>
@@ -707,6 +737,30 @@ namespace CppCore
       CppCore::addcarry32(x, y, r, c);
    }
 
+   /// <summary>
+   /// Template Specialization for 64+8=64
+   /// </summary>
+   template<> INLINE void addcarry(const uint64_t& x, const uint8_t& y, uint64_t& r, uint8_t& c)
+   {
+      CppCore::addcarry64(x, y, r, c);
+   }
+
+   /// <summary>
+   /// Template Specialization for 64+16=64
+   /// </summary>
+   template<> INLINE void addcarry(const uint64_t& x, const uint16_t& y, uint64_t& r, uint8_t& c)
+   {
+      CppCore::addcarry64(x, y, r, c);
+   }
+
+   /// <summary>
+   /// Template Specialization for 64+32=64
+   /// </summary>
+   template<> INLINE void addcarry(const uint64_t& x, const uint32_t& y, uint64_t& r, uint8_t& c)
+   {
+      CppCore::addcarry64(x, y, r, c);
+   }
+
    /// <summary>
    /// Template Specialization for 64+64=64
    /// </summary>
@@ -768,8 +822,10 @@ namespace CppCore
    template<typename UINT1, typename UINT2, typename UINT3>
    INLINE static void uadd(const UINT1& x, const UINT2& y, UINT3& r)
    {
-      uint8_t c = 0;
-      CppCore::addcarry(x, y, r, c);
+      if      constexpr (sizeof(UINT1) < sizeof(size_t)) { CppCore::uadd((size_t)x, y, r); }
+      else if constexpr (sizeof(UINT2) < sizeof(size_t)) { CppCore::uadd(x, (size_t)y, r); }
+      else if constexpr (sizeof(UINT3) < sizeof(size_t)) { size_t t; CppCore::uadd(x, y, t); r = (UINT3)t; }
+      else { uint8_t c = 0; CppCore::addcarry(x, y, r, c); }
    }
 
    /// <summary>
diff --git a/src/CppCore.Test/Test.cpp b/src/CppCore.Test/Test.cpp
index fbd16972..f6872a32 100644
--- a/src/CppCore.Test/Test.cpp
+++ b/src/CppCore.Test/Test.cpp
@@ -700,6 +700,16 @@ int main()
    TEST(CppCore::Test::Encoding::BaseX::tostring16, "tostring16: ", std::endl);
    TEST(CppCore::Test::Encoding::BaseX::tostring32, "tostring32: ", std::endl);
    TEST(CppCore::Test::Encoding::BaseX::tostring64, "tostring64: ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::parse8,     "parse8:     ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::parse16,    "parse16:    ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::parse32,    "parse32:    ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::parse64,    "parse64:    ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::parse128,   "parse128:   ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::tryparse8,  "tryparse8:  ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::tryparse16, "tryparse16: ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::tryparse32, "tryparse32: ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::tryparse64, "tryparse64: ", std::endl);
+   TEST(CppCore::Test::Encoding::BaseX::tryparse128,"tryparse128:", std::endl);
 
    std::cout << "-------------------------------" << std::endl;
    std::cout << "   CppCore::Encoding::Decimal  " << std::endl;