Fix compile-time negation and array access

1 files changed, 49 insertions, 6 deletions

diff --git a/boot/result.cc b/boot/result.cc
index f9f57db..4d4c20f 100644
--- a/boot/result.cc
+++ b/boot/result.cc
@@ -129,12 +129,14 @@ namespace elna::boot
     }
 
     integer_literal::integer_literal(integer_literal&& that) noexcept
+        : m_signed(that.is_signed()), m_size(that.size())
     {
         mpz_init(this->raw);
         mpz_swap(this->raw, that.raw);
     }
 
     integer_literal::integer_literal(const integer_literal& that)
+        : m_signed(that.is_signed()), m_size(that.size())
     {
         mpz_init(this->raw);
         mpz_set(this->raw, that.raw);
@@ -293,10 +295,7 @@ namespace elna::boot
 
     integer_literal& integer_literal::operator=(integer_literal&& that) noexcept
     {
-        if (this != &that)
-        {
-            mpz_swap(this->raw, that.raw);
-        }
+        swap(*this, that);
         return *this;
     }
 
@@ -304,11 +303,43 @@ namespace elna::boot
     {
         if (this != &that)
         {
-            mpz_set(this->raw, that.raw);
+            integer_literal temp(that);
+
+            swap(*this, temp);
         }
         return *this;
     }
 
+    std::optional<std::ptrdiff_t> integer_literal::to_signed() const
+    {
+        if (!is_signed())
+        {
+            return std::nullopt;
+        }
+        if (is_negative_minimum(sizeof(std::ptrdiff_t) * CHAR_BIT))
+        {
+            return std::numeric_limits<ptrdiff_t>::min();
+        }
+        auto [written, rop] = export_to_words<std::ptrdiff_t>();
+
+        if (written > 1 || rop < 0)
+        {
+            return std::nullopt;
+        }
+        return mpz_sgn(this->raw) < 0 ? -rop : rop;
+    }
+
+    std::optional<std::size_t> integer_literal::to_unsigned() const
+    {
+        if (is_signed())
+        {
+            return std::nullopt;
+        }
+        auto [written, rop] = export_to_words<std::size_t>();
+
+        return written > 1 ? std::nullopt : std::make_optional(rop);
+    }
+
     bool integer_literal::is_signed() const
     {
         return this->m_signed;
@@ -319,6 +350,13 @@ namespace elna::boot
         return this->m_size;
     }
 
+    void swap(integer_literal& lhs, integer_literal& rhs) noexcept
+    {
+        mpz_swap(lhs.raw, rhs.raw);
+        std::swap(lhs.m_signed, rhs.m_signed);
+        std::swap(lhs.m_size, rhs.m_size);
+    }
+
     std::optional<integer_literal> integer_literal::check() &&
     {
         std::size_t required_bits = mpz_sizeinbase(this->raw, 2);
@@ -337,9 +375,14 @@ namespace elna::boot
         }
     }
 
+    bool integer_literal::is_negative_minimum(const std::size_t bits) const
+    {
+        return mpz_sgn(this->raw) < 0 && mpz_scan1(this->raw, 0) == bits - 1;
+    }
+
     bool integer_literal::is_negative_minimum() const
     {
-        return mpz_sgn(this->raw) < 0 && mpz_scan1(this->raw, 0) == bits() - 1;
+        return is_negative_minimum(bits());
     }
 
     std::size_t integer_literal::bits() const