diff --git a/src/sled/futures/future.h b/src/sled/futures/future.h
index 139484a..a52bb07 100644
--- a/src/sled/futures/future.h
+++ b/src/sled/futures/future.h
@@ -60,7 +60,7 @@ struct FutureData {
 void SetDefaultScheduler(TaskQueueBase *scheduler) noexcept;
 TaskQueueBase *GetDefaultScheduler() noexcept;
 
-template<typename T, typename FailureT = std::exception>
+template<typename T, typename FailureT = failure::DefaultException>
 class Future {
     static_assert(!std::is_same<T, void>::value, "Future<void, _> is not allowed. Use Future<bool, _> instead");
     static_assert(!std::is_same<FailureT, void>::value, "Future<_, void> is not allowed. Use Future<_, bool> instead");
diff --git a/src/sled/futures/future_test.cc b/src/sled/futures/future_test.cc
index 92cecd7..0814648 100644
--- a/src/sled/futures/future_test.cc
+++ b/src/sled/futures/future_test.cc
@@ -113,6 +113,9 @@ TEST_SUITE("future")
             return 1;
         });
         CHECK_FALSE(f2.IsFailed());
+        CHECK_EQ(std::string("test"), f2.FailureReason().what());
+        CHECK(f2.IsFailed());
+
         auto f3 = sled::Future<std::string>::AsyncValue("11");
         CHECK_EQ(f3.Result(), "11");
     }
diff --git a/src/sled/futures/internal/failure_handling.h b/src/sled/futures/internal/failure_handling.h
index 79e1491..fa90b8d 100644
--- a/src/sled/futures/internal/failure_handling.h
+++ b/src/sled/futures/internal/failure_handling.h
@@ -3,18 +3,38 @@
 
 #pragma once
 #include "sled/any.h"
+#include "sled/nonstd/string_view.h"
 #include <string>
 
 namespace sled {
 namespace failure {
-template<typename FailureT>
+
+class DefaultException : std::exception {
+public:
+    inline DefaultException() = default;
+
+    inline DefaultException(const std::string &message) : message_(message) {}
+
+    inline DefaultException(const char *message) : message_(message) {}
+
+    ~DefaultException() noexcept override = default;
+
+    const char *what() const noexcept override { return message_.c_str(); }
+
+private:
+    std::string message_;
+};
+
+template<typename FailureT,
+         typename = typename std::enable_if<!std::is_constructible<FailureT, std::string>::value>::type>
 inline FailureT
-FailureFromString(std::string &&)
+FailureFromString(std::string &&str)
 {
     return FailureT();
 }
 
-template<typename FailureT>
+template<typename FailureT,
+         typename = typename std::enable_if<std::is_constructible<FailureT, const std::string &>::value>::type>
 inline FailureT
 FailureFromString(const std::string &str)
 {
@@ -24,9 +44,16 @@ FailureFromString(const std::string &str)
 
 template<>
 inline std::string
-FailureFromString<std::string>(std::string &&str)
+FailureFromString<std::string>(const std::string &str)
 {
-    return std::move(str);
+    return str;
+}
+
+template<>
+inline DefaultException
+FailureFromString<DefaultException>(const std::string &str)
+{
+    return DefaultException(str);
 }
 
 }// namespace failure
diff --git a/src/sled/futures/internal/promise.h b/src/sled/futures/internal/promise.h
index 79201ca..7252f85 100644
--- a/src/sled/futures/internal/promise.h
+++ b/src/sled/futures/internal/promise.h
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include "failure_handling.h"
 #include <memory>
 #include <type_traits>
 
@@ -10,7 +11,7 @@ namespace sled {
 template<typename T, typename FailureT>
 class Future;
 
-template<typename T, typename FailureT = std::exception>
+template<typename T, typename FailureT = failure::DefaultException>
 class Promise final {
     static_assert(!std::is_same<T, void>::value, "Promise<void, _> is not allowed. Use Promise<bool, _> instead");
     static_assert(!std::is_same<FailureT, void>::value,
diff --git a/src/sled/numerics/int128.h b/src/sled/numerics/int128.h
new file mode 100644
index 0000000..d184000
--- /dev/null
+++ b/src/sled/numerics/int128.h
@@ -0,0 +1,61 @@
+#ifndef SLED_NUMERICS_INT128_H
+#define SLED_NUMERICS_INT128_H
+#include <string>
+
+#pragma once
+
+namespace sled {
+class Int128 {
+    constexpr Int128(int v);
+    constexpr Int128(unsigned int v);
+    constexpr Int128(long v);
+    constexpr Int128(unsigned long v);
+    constexpr Int128(long long v);
+    constexpr Int128(unsigned long long v);
+    constexpr Int128(const Int128 &v);
+
+    Int128 &operator=(int v);
+    Int128 &operator=(unsigned int v);
+    Int128 &operator=(long v);
+    Int128 &operator=(unsigned long v);
+    Int128 &operator=(long long v);
+    Int128 &operator=(unsigned long long v);
+    Int128 &operator=(const Int128 &v);
+
+    Int128 &operator+=(const Int128 &v);
+    Int128 &operator-=(const Int128 &v);
+    Int128 &operator*=(const Int128 &v);
+    Int128 &operator/=(const Int128 &v);
+    Int128 &operator%=(const Int128 &v);
+    Int128 &operator++(int);
+    Int128 &operator--(int);
+    Int128 &operator&=(const Int128 &v);
+    Int128 &operator|=(const Int128 &v);
+    Int128 &operator^=(const Int128 &v);
+    Int128 &operator<<=(int v);
+    Int128 &operator>>=(int v);
+
+    constexpr explicit operator bool() const;
+    constexpr explicit operator char() const;
+    constexpr explicit operator unsigned char() const;
+    constexpr explicit operator short() const;
+    constexpr explicit operator unsigned short() const;
+    constexpr explicit operator int() const;
+    constexpr explicit operator unsigned int() const;
+    constexpr explicit operator long() const;
+    constexpr explicit operator unsigned long() const;
+    constexpr explicit operator long long() const;
+    constexpr explicit operator unsigned long long() const;
+    explicit operator float() const;
+    explicit operator double() const;
+    explicit operator long double() const;
+
+private:
+    std::string ToString() const;
+
+    uint64_t lo_;
+    uint64_t hi_;
+};
+}// namespace sled
+
+#endif// SLED_NUMERICS_INT128_H
diff --git a/src/sled/units/timestamp.h b/src/sled/units/timestamp.h
index 11f05d7..a454b74 100644
--- a/src/sled/units/timestamp.h
+++ b/src/sled/units/timestamp.h
@@ -108,7 +108,7 @@ public:
         } else if (IsMinusInfinity() || other.IsPlusInfinity()) {
             return TimeDelta::MinusInfinity();
         }
-        return TimeDelta::Micros(us() - other.us());
+        return TimeDelta::Nanos(ns() - other.ns());
     }
 
     Timestamp &operator-=(const TimeDelta delta)