From 2ee39ed5f0dd2eab860547d64711103df88e1aca Mon Sep 17 00:00:00 2001
From: Daniel Bertalan <dani@danielbertalan.dev>
Date: Mon, 5 Jul 2021 20:14:29 +0200
Subject: [PATCH] AK: Fix `UFixedBigInt` not building with Clang

Clang does not like that we are trying to refer to our own size while
our declaration is not yet complete, and fails to compile this file.
This is fixed by introducing a function which returns the correct
sizeof. This only gets evaluated in the `requires` clause after the
whole class has been parsed, so it will compile fine.
---
 AK/UFixedBigInt.h | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/AK/UFixedBigInt.h b/AK/UFixedBigInt.h
index d1dc13eba9..9cb0cace61 100644
--- a/AK/UFixedBigInt.h
+++ b/AK/UFixedBigInt.h
@@ -54,7 +54,6 @@ public:
         , m_high(high)
     {
     }
-
     constexpr T& low()
     {
         return m_low;
@@ -314,6 +313,11 @@ public:
         return *this;
     }
 
+    static constexpr size_t my_size()
+    {
+        return sizeof(R);
+    }
+
     // Arithmetics
 
     // implies size of less than u64, so passing references isn't useful
@@ -335,7 +339,7 @@ public:
         };
     }
     template<Unsigned U>
-    requires(sizeof(R) > sizeof(U) && sizeof(T) > sizeof(u64)) constexpr R addc(const U& other, bool& carry) const
+    requires(my_size() > sizeof(U) && sizeof(T) > sizeof(u64)) constexpr R addc(const U& other, bool& carry) const
     {
         T lower = m_low.addc(other, carry);
         T higher = m_high.addc(0u, carry);
@@ -377,7 +381,7 @@ public:
         };
     }
     template<Unsigned U>
-    requires(sizeof(R) < sizeof(U)) constexpr U addc(const U& other, bool& carry) const
+    requires(my_size() < sizeof(U)) constexpr U addc(const U& other, bool& carry) const
     {
         return other.addc(*this, carry);
     }
@@ -474,7 +478,7 @@ public:
 
     // FIXME: no restraints on this
     template<Unsigned U>
-    requires(sizeof(R) >= sizeof(U)) constexpr R div_mod(const U& divisor, U& remainder) const
+    requires(my_size() >= sizeof(U)) constexpr R div_mod(const U& divisor, U& remainder) const
     {
         // FIXME: Is there a better way to raise a division by 0?
         //        Maybe as a compiletime warning?