From 54e45d113d3509920e5620336ac355bb7229c57b Mon Sep 17 00:00:00 2001
From: CardinalPrefect <rumpel135@gmail.com>
Date: Sat, 12 Jun 2021 14:58:35 +0300
Subject: [PATCH 1/5] optional solution

---
 module-1/homework/Optional/optional.h | 203 +++++++++++++++++++++++++-
 1 file changed, 196 insertions(+), 7 deletions(-)

diff --git a/module-1/homework/Optional/optional.h b/module-1/homework/Optional/optional.h
index 1c2bbf91..cf95a1df 100644
--- a/module-1/homework/Optional/optional.h
+++ b/module-1/homework/Optional/optional.h
@@ -6,21 +6,115 @@
 namespace task {
 
 struct NullOpt {
-    // Your code goes here;
+    explicit constexpr NullOpt(int) {
+    }
 };
 
-constexpr NullOpt kNullOpt = // Your code goes here;
-
+constexpr NullOpt kNullOpt = NullOpt(0);
 struct InPlace {
-    // Your code goes here;
+    explicit InPlace() = default;
 };
 
-constexpr InPlace kInPlace =  //Your code goes here;
+constexpr InPlace kInPlace = InPlace();
+
+template <typename T, bool>
+class OptionalBase {
+public:
+    constexpr OptionalBase() {
+    }
+
+    constexpr OptionalBase(NullOpt) { // NOLINT
+    }
+
+    template <typename... Args>
+    constexpr OptionalBase(InPlace, Args&&... args) 
+        : value_(std::forward<Args>(args)...), 
+          is_none_(false) {
+    }
+
+    template <typename U = T>
+    constexpr OptionalBase(U&& value) 
+        : value_(std::forward<U>(value)),
+          is_none_(false) {
+    }
+
+protected:
+    template <typename U = T>
+    void Set(U&& value) {
+        value_ = std::forward<U>(value);
+        is_none_ = false;
+    }
+
+    void Reset() {
+        is_none_ = true;
+    }
+
+    union {
+        T value_;
+        char none_;
+    };
+
+    bool is_none_ = true;
+};
 
 template <typename T>
-class Optional : public // Your code goes here; {
+class OptionalBase<T, false> {
 public:
-    using value_type =  // Your code goes here;
+    constexpr OptionalBase() {
+    }
+
+    constexpr OptionalBase(NullOpt) { // NOLINT
+    }
+
+    template <typename... Args>
+    constexpr OptionalBase(InPlace, Args&&... args)
+        : value_(std::forward<Args>(args)...),
+          is_none_(false) {
+    }
+
+    template <typename U = T>
+    constexpr OptionalBase(U&& value) 
+        : value_(std::forward<U>(value)),
+          is_none_(false) {
+    }
+
+    ~OptionalBase() {
+        if (!is_none_) {
+            value_.~T();
+        }
+    }
+
+protected:
+    template <typename U = T>
+    void Set(U&& value) {
+        if (!is_none_) {
+            value_.~T();
+        }
+        value_ = std::forward<U>(value);
+        is_none_ = false;
+    }
+
+    void Reset() {
+        if (!is_none_) {
+            value_.~T();
+        }
+        is_none_ = true;
+    }
+
+    union {
+        T value_;
+        char none_;
+    };
+
+    bool is_none_ = true;
+};
+
+template <typename T>
+class Optional : public OptionalBase<T, std::is_trivially_destructible_v<T>> {
+private:
+    using base = OptionalBase<T, std::is_trivially_destructible<T>::value>;
+public:
+    using value_type = T;
 
     constexpr Optional() noexcept;
 
@@ -61,4 +155,99 @@ class Optional : public // Your code goes here; {
 
     constexpr value_type&& operator*() &&;
 };
+
+template <typename T>
+constexpr Optional<T>::Optional() noexcept {
+}
+
+template <typename T>
+template <typename U>
+constexpr Optional<T>::Optional(U&& value) : base(std::forward<U>(value)) {
+}
+
+template <typename T>
+constexpr Optional<T>::Optional(NullOpt) noexcept {
+}
+
+template <typename T>
+template <typename... Args>
+constexpr Optional<T>::Optional(InPlace, Args&&... args)
+    : base{kInPlace, std::forward<Args>(args)...} {
+}
+
+template <typename T>
+Optional<T>& Optional<T>::operator=(NullOpt) noexcept {
+    base::Reset();
+    return *this;
+}
+
+template <typename T>
+template <typename U>
+Optional<T>& Optional<T>::operator=(U&& value) {
+    base::Set(std::forward<U>(value));
+    return *this;
+}
+
+template <typename T>
+void Optional<T>::Reset() noexcept {
+    base::Reset();
+}
+
+template <typename T>
+template <typename U>
+constexpr T Optional<T>::ValueOr(U&& default_value) const& {
+    if (!base::is_none_) {
+        return base::value_;
+    }
+    return default_value;
+}
+
+template <typename T>
+template <typename U>
+constexpr T Optional<T>::ValueOr(U&& default_value) && {
+    if (!base::is_none_) {
+        return base::value_;
+    }
+    return default_value;
+}
+
+template <typename T>
+constexpr bool Optional<T>::HasValue() const noexcept {
+    return !base::is_none_;
+}
+
+template <typename T>
+constexpr Optional<T>::operator bool() const noexcept {
+    return HasValue();
+}
+
+template <typename T>
+constexpr std::add_pointer_t<const typename Optional<T>::value_type> Optional<T>::operator->() const {
+    return base::value_;
+}
+
+template <typename T>
+constexpr std::add_pointer_t<typename Optional<T>::value_type> Optional<T>::operator->() {
+    return &(base::value_);
+}
+
+template <typename T>
+constexpr const typename Optional<T>::value_type& Optional<T>::operator*() const& {
+    return base::value_;
+}
+
+template <typename T>
+constexpr typename Optional<T>::value_type& Optional<T>::operator*() & {
+    return base::value_;
+}
+
+template <typename T>
+constexpr const typename Optional<T>::value_type&& Optional<T>::operator*() const&& {
+    return std::move(base::value_);
+}
+
+template <typename T>
+constexpr typename Optional<T>::value_type&& Optional<T>::operator*() && {
+    return std::move(base::value_);
+}
 }  // namespace task
\ No newline at end of file

From a195b3b9387064361ecf0d21293f514016744fc4 Mon Sep 17 00:00:00 2001
From: CardinalPrefect <rumpel135@gmail.com>
Date: Sat, 12 Jun 2021 15:06:30 +0300
Subject: [PATCH 2/5] optional solution 2.0

---
 module-1/homework/Optional/optional.h | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/module-1/homework/Optional/optional.h b/module-1/homework/Optional/optional.h
index cf95a1df..6140e13e 100644
--- a/module-1/homework/Optional/optional.h
+++ b/module-1/homework/Optional/optional.h
@@ -23,17 +23,18 @@ class OptionalBase {
     constexpr OptionalBase() {
     }
 
-    constexpr OptionalBase(NullOpt) { // NOLINT
+    constexpr OptionalBase(NullOpt) // NOLINT
+    {
     }
 
     template <typename... Args>
-    constexpr OptionalBase(InPlace, Args&&... args) 
+    constexpr OptionalBase(InPlace, Args&&... args) // NOLINT
         : value_(std::forward<Args>(args)...), 
           is_none_(false) {
     }
 
     template <typename U = T>
-    constexpr OptionalBase(U&& value) 
+    constexpr OptionalBase(U&& value) // NOLINT
         : value_(std::forward<U>(value)),
           is_none_(false) {
     }
@@ -63,17 +64,18 @@ class OptionalBase<T, false> {
     constexpr OptionalBase() {
     }
 
-    constexpr OptionalBase(NullOpt) { // NOLINT
+    constexpr OptionalBase(NullOpt) // NOLINT
+    {
     }
 
     template <typename... Args>
-    constexpr OptionalBase(InPlace, Args&&... args)
+    constexpr OptionalBase(InPlace, Args&&... args) // NOLINT
         : value_(std::forward<Args>(args)...),
           is_none_(false) {
     }
 
     template <typename U = T>
-    constexpr OptionalBase(U&& value) 
+    constexpr OptionalBase(U&& value) // NOLINT
         : value_(std::forward<U>(value)),
           is_none_(false) {
     }
@@ -113,6 +115,7 @@ template <typename T>
 class Optional : public OptionalBase<T, std::is_trivially_destructible_v<T>> {
 private:
     using base = OptionalBase<T, std::is_trivially_destructible<T>::value>;
+
 public:
     using value_type = T;
 
@@ -222,7 +225,8 @@ constexpr Optional<T>::operator bool() const noexcept {
 }
 
 template <typename T>
-constexpr std::add_pointer_t<const typename Optional<T>::value_type> Optional<T>::operator->() const {
+constexpr std::add_pointer_t<const typename Optional<T>::value_type> Optional<T>::operator->() 
+    const {
     return base::value_;
 }
 

From 095d00842c0bf1925c2b74e777eb0e6a1c199e54 Mon Sep 17 00:00:00 2001
From: CardinalPrefect <rumpel135@gmail.com>
Date: Sat, 12 Jun 2021 15:09:25 +0300
Subject: [PATCH 3/5] optional solution 2.0

---
 module-1/homework/Optional/optional.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/module-1/homework/Optional/optional.h b/module-1/homework/Optional/optional.h
index 6140e13e..2a450ca1 100644
--- a/module-1/homework/Optional/optional.h
+++ b/module-1/homework/Optional/optional.h
@@ -23,18 +23,18 @@ class OptionalBase {
     constexpr OptionalBase() {
     }
 
-    constexpr OptionalBase(NullOpt) // NOLINT
+    constexpr OptionalBase(NullOpt)  // NOLINT
     {
     }
 
     template <typename... Args>
-    constexpr OptionalBase(InPlace, Args&&... args) // NOLINT
+    constexpr OptionalBase(InPlace, Args&&... args)  // NOLINT
         : value_(std::forward<Args>(args)...), 
           is_none_(false) {
     }
 
     template <typename U = T>
-    constexpr OptionalBase(U&& value) // NOLINT
+    constexpr OptionalBase(U&& value)  // NOLINT
         : value_(std::forward<U>(value)),
           is_none_(false) {
     }
@@ -64,18 +64,18 @@ class OptionalBase<T, false> {
     constexpr OptionalBase() {
     }
 
-    constexpr OptionalBase(NullOpt) // NOLINT
+    constexpr OptionalBase(NullOpt)  // NOLINT
     {
     }
 
     template <typename... Args>
-    constexpr OptionalBase(InPlace, Args&&... args) // NOLINT
+    constexpr OptionalBase(InPlace, Args&&... args)  // NOLINT
         : value_(std::forward<Args>(args)...),
           is_none_(false) {
     }
 
     template <typename U = T>
-    constexpr OptionalBase(U&& value) // NOLINT
+    constexpr OptionalBase(U&& value)  // NOLINT
         : value_(std::forward<U>(value)),
           is_none_(false) {
     }

From 1df3a222dc5850b7727c83e178bc0fea1d2bb17d Mon Sep 17 00:00:00 2001
From: CardinalPrefect <rumpel135@gmail.com>
Date: Sat, 12 Jun 2021 15:14:20 +0300
Subject: [PATCH 4/5] optional solution 2.2

---
 module-1/homework/Optional/optional.h | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/module-1/homework/Optional/optional.h b/module-1/homework/Optional/optional.h
index 2a450ca1..f41f5533 100644
--- a/module-1/homework/Optional/optional.h
+++ b/module-1/homework/Optional/optional.h
@@ -29,14 +29,12 @@ class OptionalBase {
 
     template <typename... Args>
     constexpr OptionalBase(InPlace, Args&&... args)  // NOLINT
-        : value_(std::forward<Args>(args)...), 
-          is_none_(false) {
+        : value_(std::forward<Args>(args)...), is_none_(false) {
     }
 
     template <typename U = T>
     constexpr OptionalBase(U&& value)  // NOLINT
-        : value_(std::forward<U>(value)),
-          is_none_(false) {
+        : value_(std::forward<U>(value)), is_none_(false) {
     }
 
 protected:
@@ -70,14 +68,12 @@ class OptionalBase<T, false> {
 
     template <typename... Args>
     constexpr OptionalBase(InPlace, Args&&... args)  // NOLINT
-        : value_(std::forward<Args>(args)...),
-          is_none_(false) {
+        : value_(std::forward<Args>(args)...), is_none_(false) {
     }
 
     template <typename U = T>
     constexpr OptionalBase(U&& value)  // NOLINT
-        : value_(std::forward<U>(value)),
-          is_none_(false) {
+        : value_(std::forward<U>(value)), is_none_(false) {
     }
 
     ~OptionalBase() {
@@ -225,7 +221,7 @@ constexpr Optional<T>::operator bool() const noexcept {
 }
 
 template <typename T>
-constexpr std::add_pointer_t<const typename Optional<T>::value_type> Optional<T>::operator->() 
+constexpr std::add_pointer_t<const typename Optional<T>::value_type> Optional<T>::operator->()
     const {
     return base::value_;
 }

From fb9a2aac1b2f0681b4b22be65db053dfbdad3371 Mon Sep 17 00:00:00 2001
From: CardinalPrefect <rumpel135@gmail.com>
Date: Sat, 12 Jun 2021 20:41:58 +0300
Subject: [PATCH 5/5] changed () -> {}

---
 module-1/homework/Optional/optional.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/module-1/homework/Optional/optional.h b/module-1/homework/Optional/optional.h
index f41f5533..f10ad2da 100644
--- a/module-1/homework/Optional/optional.h
+++ b/module-1/homework/Optional/optional.h
@@ -29,12 +29,12 @@ class OptionalBase {
 
     template <typename... Args>
     constexpr OptionalBase(InPlace, Args&&... args)  // NOLINT
-        : value_(std::forward<Args>(args)...), is_none_(false) {
+        : value_{std::forward<Args>(args)...}, is_none_{false} {
     }
 
     template <typename U = T>
     constexpr OptionalBase(U&& value)  // NOLINT
-        : value_(std::forward<U>(value)), is_none_(false) {
+        : value_{std::forward<U>(value)}, is_none_{false} {
     }
 
 protected:
@@ -68,12 +68,12 @@ class OptionalBase<T, false> {
 
     template <typename... Args>
     constexpr OptionalBase(InPlace, Args&&... args)  // NOLINT
-        : value_(std::forward<Args>(args)...), is_none_(false) {
+        : value_{std::forward<Args>(args)...}, is_none_{false} {
     }
 
     template <typename U = T>
     constexpr OptionalBase(U&& value)  // NOLINT
-        : value_(std::forward<U>(value)), is_none_(false) {
+        : value_{std::forward<U>(value)}, is_none_{false} {
     }
 
     ~OptionalBase() {
@@ -161,7 +161,7 @@ constexpr Optional<T>::Optional() noexcept {
 
 template <typename T>
 template <typename U>
-constexpr Optional<T>::Optional(U&& value) : base(std::forward<U>(value)) {
+constexpr Optional<T>::Optional(U&& value) : base{std::forward<U>(value)} {
 }
 
 template <typename T>