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Add type-safe GetTypeIndex instead of hardcoded index lookups

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Signed-off-by: Nicholas Van Sickle <nvsickle@amazon.com>
This commit is contained in:
Nicholas Van Sickle
2021-12-20 18:27:00 -08:00
parent bbd00adade
commit 1da99eaea0
2 changed files with 97 additions and 53 deletions
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Code/Framework/AzCore/AzCore/DOM/DomValue.cpp
+70 -26
View File
@@ -26,6 +26,51 @@ namespace AZ::Dom
return refCountedPointer;
}
namespace Internal
{
template<class TestType>
constexpr size_t GetTypeIndexInternal(size_t index = 0)
{
static_assert(false, "Type not found in ValueType");
return index;
}
template<class TestType, class FirstType, class... Rest>
constexpr size_t GetTypeIndexInternal(size_t index = 0)
{
if constexpr (AZStd::is_same_v<TestType, FirstType>)
{
return index;
}
else
{
return GetTypeIndexInternal<TestType, Rest...>(index + 1);
}
}
template<typename T>
struct ExtractTypeArgs
{
};
template<template<typename...> class TypeToExtract, typename... Args>
struct ExtractTypeArgs<TypeToExtract<Args...>>
{
template<class T>
static constexpr size_t GetTypeIndex()
{
return GetTypeIndexInternal<T, Args...>();
}
};
} // namespace Internal
// Helper function, looks up the index of a type within Value::m_value's storage
template<class T>
constexpr size_t GetTypeIndex()
{
return Internal::ExtractTypeArgs<Value::ValueType>::GetTypeIndex<T>();
}
Node::Node(AZ::Name name)
: m_name(name)
{
@@ -227,27 +272,27 @@ namespace AZ::Dom
{
switch (m_value.index())
{
case 0: // AZStd::monostate
case GetTypeIndex<AZStd::monostate>():
return Type::Null;
case 1: // int64_t
case GetTypeIndex<int64_t>():
return Type::Int64;
case 2: // uint64_t
case GetTypeIndex<uint64_t>():
return Type::Uint64;
case 3: // double
case GetTypeIndex<double>():
return Type::Double;
case 4: // bool
case GetTypeIndex<bool>():
return Type::Bool;
case 5: // AZStd::string_view
case 6: // AZStd::shared_ptr<const AZStd::string>
case 7: // ShortStringType
case GetTypeIndex<AZStd::string_view>():
case GetTypeIndex<SharedStringType>():
case GetTypeIndex<ShortStringType>():
return Type::String;
case 8: // ObjectPtr
case GetTypeIndex<ObjectPtr>():
return Type::Object;
case 9: // ArrayPtr
case GetTypeIndex<ArrayPtr>():
return Type::Array;
case 10: // NodePtr
case GetTypeIndex<NodePtr>():
return Type::Node;
case 11: // AZStd::any*
case GetTypeIndex<AZStd::shared_ptr<AZStd::any>>():
return Type::Opaque;
}
AZ_Assert(false, "AZ::Dom::Value::GetType: m_value has an unexpected type");
@@ -813,11 +858,11 @@ namespace AZ::Dom
{
switch (m_value.index())
{
case 1: // int64_t
case GetTypeIndex<int64_t>():
return AZStd::get<int64_t>(m_value);
case 2: // uint64_t
case GetTypeIndex<uint64_t>():
return aznumeric_cast<int64_t>(AZStd::get<uint64_t>(m_value));
case 3: // double
case GetTypeIndex<double>():
return aznumeric_cast<int64_t>(AZStd::get<double>(m_value));
}
AZ_Assert(false, "AZ::Dom::Value: Called GetInt on a non-numeric type");
@@ -843,11 +888,11 @@ namespace AZ::Dom
{
switch (m_value.index())
{
case 1: // int64_t
case GetTypeIndex<int64_t>():
return aznumeric_cast<uint64_t>(AZStd::get<int64_t>(m_value));
case 2: // uint64_t
case GetTypeIndex<uint64_t>():
return AZStd::get<uint64_t>(m_value);
case 3: // double
case GetTypeIndex<double>():
return aznumeric_cast<uint64_t>(AZStd::get<double>(m_value));
}
AZ_Assert(false, "AZ::Dom::Value: Called GetInt on a non-numeric type");
@@ -888,11 +933,11 @@ namespace AZ::Dom
{
switch (m_value.index())
{
case 1: // int64_t
case GetTypeIndex<int64_t>():
return aznumeric_cast<double>(AZStd::get<int64_t>(m_value));
case 2: // uint64_t
case GetTypeIndex<uint64_t>():
return aznumeric_cast<double>(AZStd::get<uint64_t>(m_value));
case 3: // double
case GetTypeIndex<double>():
return AZStd::get<double>(m_value);
}
AZ_Assert(false, "AZ::Dom::Value: Called GetInt on a non-numeric type");
@@ -923,14 +968,14 @@ namespace AZ::Dom
{
switch (m_value.index())
{
case 5: // AZStd::string_view
case GetTypeIndex<AZStd::string_view>():
return AZStd::get<AZStd::string_view>(m_value);
case 6: // AZStd::shared_ptr<AZStd::vector<char>>
case GetTypeIndex<SharedStringType>():
{
auto& buffer = *AZStd::get<SharedStringType>(m_value);
return { buffer.data(), buffer.size() };
}
case 7: // ShortStringType
case GetTypeIndex<ShortStringType>():
{
const ShortStringType& shortString = AZStd::get<ShortStringType>(m_value);
return { shortString.data(), shortString.size() };
@@ -965,8 +1010,7 @@ namespace AZ::Dom
}
else
{
SharedStringType sharedString =
AZStd::allocate_shared<SharedStringContainer>(StdValueAllocator(), value.begin(), value.end());
SharedStringType sharedString = AZStd::allocate_shared<SharedStringContainer>(StdValueAllocator(), value.begin(), value.end());
m_value = AZStd::move(sharedString);
}
}
Code/Framework/AzCore/AzCore/DOM/DomValue.h
+27 -27
View File
@@ -159,6 +159,33 @@ namespace AZ::Dom
using SharedStringContainer = AZStd::vector<char>;
using SharedStringType = AZStd::shared_ptr<const SharedStringContainer>;
//! The internal storage type for Value.
//! These types do not correspond one-to-one with the Value's external Type as there may be multiple storage classes
//! for the same type in some instances, such as string storage.
using ValueType = AZStd::variant<
// Null
AZStd::monostate,
// Int64
int64_t,
// Uint64
uint64_t,
// Double
double,
// Bool
bool,
// StringType
AZStd::string_view,
SharedStringType,
ShortStringType,
// Object
ObjectPtr,
// Array
ArrayPtr,
// Node
NodePtr,
// Opaque
AZStd::shared_ptr<AZStd::any>>;
// Constructors...
Value();
Value(const Value&);
@@ -347,33 +374,6 @@ namespace AZ::Dom
explicit Value(const AZStd::any& opaqueValue);
//! The internal storage type for Value.
//! These types do not correspond one-to-one with the Value's external Type as there may be multiple storage classes
//! for the same type in some instances, such as string storage.
using ValueType = AZStd::variant<
// Null
AZStd::monostate,
// Int64
int64_t,
// Uint64
uint64_t,
// Double
double,
// Bool
bool,
// StringType
AZStd::string_view,
SharedStringType,
ShortStringType,
// Object
ObjectPtr,
// Array
ArrayPtr,
// Node
NodePtr,
// Opaque
AZStd::shared_ptr<AZStd::any>>;
static_assert(
sizeof(ValueType) == sizeof(ShortStringType) + sizeof(size_t), "ValueType should have no members larger than ShortStringType");