[PATCH 02/11] libcamera: yaml_parser: Delegate YamlObject::get() to helper structure
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu Jun 13 03:39:35 CEST 2024
The YamlObject::get() function is a function template that gets fully
specialized for various types. This works fine for non-template types,
but specializing it for template types (e.g. a std::vector<U>) would
require partial template specialization, which C++ allows for classes
and variables but not functions.
To work around this problem, delegate the implementation to a new
YamlObject::Getter structure template, which will support partial
specialization.
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
include/libcamera/internal/yaml_parser.h | 12 +++-
src/libcamera/yaml_parser.cpp | 78 +++++++++++++-----------
2 files changed, 55 insertions(+), 35 deletions(-)
diff --git a/include/libcamera/internal/yaml_parser.h b/include/libcamera/internal/yaml_parser.h
index 81cc0e25ae0f..06a41146ad01 100644
--- a/include/libcamera/internal/yaml_parser.h
+++ b/include/libcamera/internal/yaml_parser.h
@@ -162,7 +162,10 @@ public:
std::size_t size() const;
template<typename T>
- std::optional<T> get() const;
+ std::optional<T> get() const
+ {
+ return Getter<T>{}.get(*this);
+ }
template<typename T, typename U>
T get(U &&defaultValue) const
@@ -199,6 +202,8 @@ public:
private:
LIBCAMERA_DISABLE_COPY_AND_MOVE(YamlObject)
+ template<typename T>
+ friend struct Getter;
friend class YamlParserContext;
enum class Type {
@@ -207,6 +212,11 @@ private:
Value,
};
+ template<typename T>
+ struct Getter {
+ std::optional<T> get(const YamlObject &obj) const;
+ };
+
Type type_;
std::string value_;
diff --git a/src/libcamera/yaml_parser.cpp b/src/libcamera/yaml_parser.cpp
index b68a44c15c35..56670ba7a584 100644
--- a/src/libcamera/yaml_parser.cpp
+++ b/src/libcamera/yaml_parser.cpp
@@ -118,14 +118,15 @@ std::size_t YamlObject::size() const
#ifndef __DOXYGEN__
template<>
-std::optional<bool> YamlObject::get() const
+std::optional<bool>
+YamlObject::Getter<bool>::get(const YamlObject &obj) const
{
- if (type_ != Type::Value)
+ if (obj.type_ != Type::Value)
return std::nullopt;
- if (value_ == "true")
+ if (obj.value_ == "true")
return true;
- else if (value_ == "false")
+ else if (obj.value_ == "false")
return false;
return std::nullopt;
@@ -182,14 +183,15 @@ bool parseUnsignedInteger(const std::string &str, unsigned long max,
} /* namespace */
template<>
-std::optional<int8_t> YamlObject::get() const
+std::optional<int8_t>
+YamlObject::Getter<int8_t>::get(const YamlObject &obj) const
{
- if (type_ != Type::Value)
+ if (obj.type_ != Type::Value)
return std::nullopt;
long value;
- if (!parseSignedInteger(value_, std::numeric_limits<int8_t>::min(),
+ if (!parseSignedInteger(obj.value_, std::numeric_limits<int8_t>::min(),
std::numeric_limits<int8_t>::max(), &value))
return std::nullopt;
@@ -197,14 +199,15 @@ std::optional<int8_t> YamlObject::get() const
}
template<>
-std::optional<uint8_t> YamlObject::get() const
+std::optional<uint8_t>
+YamlObject::Getter<uint8_t>::get(const YamlObject &obj) const
{
- if (type_ != Type::Value)
+ if (obj.type_ != Type::Value)
return std::nullopt;
unsigned long value;
- if (!parseUnsignedInteger(value_, std::numeric_limits<uint8_t>::max(),
+ if (!parseUnsignedInteger(obj.value_, std::numeric_limits<uint8_t>::max(),
&value))
return std::nullopt;
@@ -212,14 +215,15 @@ std::optional<uint8_t> YamlObject::get() const
}
template<>
-std::optional<int16_t> YamlObject::get() const
+std::optional<int16_t>
+YamlObject::Getter<int16_t>::get(const YamlObject &obj) const
{
- if (type_ != Type::Value)
+ if (obj.type_ != Type::Value)
return std::nullopt;
long value;
- if (!parseSignedInteger(value_, std::numeric_limits<int16_t>::min(),
+ if (!parseSignedInteger(obj.value_, std::numeric_limits<int16_t>::min(),
std::numeric_limits<int16_t>::max(), &value))
return std::nullopt;
@@ -227,14 +231,15 @@ std::optional<int16_t> YamlObject::get() const
}
template<>
-std::optional<uint16_t> YamlObject::get() const
+std::optional<uint16_t>
+YamlObject::Getter<uint16_t>::get(const YamlObject &obj) const
{
- if (type_ != Type::Value)
+ if (obj.type_ != Type::Value)
return std::nullopt;
unsigned long value;
- if (!parseUnsignedInteger(value_, std::numeric_limits<uint16_t>::max(),
+ if (!parseUnsignedInteger(obj.value_, std::numeric_limits<uint16_t>::max(),
&value))
return std::nullopt;
@@ -242,14 +247,15 @@ std::optional<uint16_t> YamlObject::get() const
}
template<>
-std::optional<int32_t> YamlObject::get() const
+std::optional<int32_t>
+YamlObject::Getter<int32_t>::get(const YamlObject &obj) const
{
- if (type_ != Type::Value)
+ if (obj.type_ != Type::Value)
return std::nullopt;
long value;
- if (!parseSignedInteger(value_, std::numeric_limits<int32_t>::min(),
+ if (!parseSignedInteger(obj.value_, std::numeric_limits<int32_t>::min(),
std::numeric_limits<int32_t>::max(), &value))
return std::nullopt;
@@ -257,14 +263,15 @@ std::optional<int32_t> YamlObject::get() const
}
template<>
-std::optional<uint32_t> YamlObject::get() const
+std::optional<uint32_t>
+YamlObject::Getter<uint32_t>::get(const YamlObject &obj) const
{
- if (type_ != Type::Value)
+ if (obj.type_ != Type::Value)
return std::nullopt;
unsigned long value;
- if (!parseUnsignedInteger(value_, std::numeric_limits<uint32_t>::max(),
+ if (!parseUnsignedInteger(obj.value_, std::numeric_limits<uint32_t>::max(),
&value))
return std::nullopt;
@@ -272,18 +279,19 @@ std::optional<uint32_t> YamlObject::get() const
}
template<>
-std::optional<double> YamlObject::get() const
+std::optional<double>
+YamlObject::Getter<double>::get(const YamlObject &obj) const
{
- if (type_ != Type::Value)
+ if (obj.type_ != Type::Value)
return std::nullopt;
- if (value_ == "")
+ if (obj.value_ == "")
return std::nullopt;
char *end;
errno = 0;
- double value = utils::strtod(value_.c_str(), &end);
+ double value = utils::strtod(obj.value_.c_str(), &end);
if ('\0' != *end || errno == ERANGE)
return std::nullopt;
@@ -292,28 +300,30 @@ std::optional<double> YamlObject::get() const
}
template<>
-std::optional<std::string> YamlObject::get() const
+std::optional<std::string>
+YamlObject::Getter<std::string>::get(const YamlObject &obj) const
{
- if (type_ != Type::Value)
+ if (obj.type_ != Type::Value)
return std::nullopt;
- return value_;
+ return obj.value_;
}
template<>
-std::optional<Size> YamlObject::get() const
+std::optional<Size>
+YamlObject::Getter<Size>::get(const YamlObject &obj) const
{
- if (type_ != Type::List)
+ if (obj.type_ != Type::List)
return std::nullopt;
- if (list_.size() != 2)
+ if (obj.list_.size() != 2)
return std::nullopt;
- auto width = list_[0].value->get<uint32_t>();
+ auto width = obj.list_[0].value->get<uint32_t>();
if (!width)
return std::nullopt;
- auto height = list_[1].value->get<uint32_t>();
+ auto height = obj.list_[1].value->get<uint32_t>();
if (!height)
return std::nullopt;
--
Regards,
Laurent Pinchart
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