hdf5::Path Class Reference

path to a node object More...

#include <path.hpp>

Public Types
using	value_type = std::string
using	iterator = std::list< value_type >::iterator
using	const_iterator = std::list< value_type >::const_iterator
using	reverse_iterator = std::list< value_type >::reverse_iterator
using	const_reverse_iterator = std::list< value_type >::const_reverse_iterator

Public Member Functions
	Path ()
	default constructor More...
	Path (const std::string &str)
	constructor More...
	Path (const char *str)
	Path (const_iterator first_element, const_iterator last_element)
	constructor from iterators More...
	operator std::string () const
size_t	size () const noexcept
	return number of path elements More...
const_iterator	begin () const
	get forward iterators More...
const_iterator	end () const
const_reverse_iterator	rbegin () const
	get reverse iterator More...
const_reverse_iterator	rend () const
bool	absolute () const noexcept
	returns true if a path is absolute More...
void	absolute (bool value) noexcept
	set a path to be absolute More...
bool	is_root () const
	true if the path refers to the root group More...
bool	is_name () const
	true if the path is a valid child name More...
std::string	name () const
	get object name from a path More...
Path	parent () const
	get parent path More...
void	append (const Path &p)
	append a path to this instance More...
Path	relative_to (const Path &base) const
Path &	operator+= (const Path &other)

Detailed Description

Every object within an HDF5 file can be addressed via a path. Such a path is a list of link names separated by a slash /. While HDF5s C-API uses a simple string to represent a path, the C++ wrapper provides a class for this purpose.

Though an HDF5 path look quit similar to an Unix filesystem path there is one major difference: .. has no special meaning. On a Unix filesystem .. would reference to the directory above the current one. In HDF5 .. simply means nothing. It would be even allowed to use .. as a name for a group, dataset or committed datatype.

Member Typedef Documentation

const_iterator

using hdf5::Path::const_iterator = std::list<value_type>::const_iterator

const_reverse_iterator

using hdf5::Path::const_reverse_iterator = std::list<value_type>::const_reverse_iterator

iterator

using hdf5::Path::iterator = std::list<value_type>::iterator

reverse_iterator

using hdf5::Path::reverse_iterator = std::list<value_type>::reverse_iterator

value_type

using hdf5::Path::value_type = std::string

Constructor & Destructor Documentation

Path() [1/4]

hdf5::Path::Path

(

)

After default construction is list of path elements is empty and the absolute path flag is set to false.

Path() [2/4]

hdf5::Path::Path

(

const std::string &

str

)

Construct a path from a string. We use an explicit constructor here to avoid accidental conversions.

Path() [3/4]

hdf5::Path::Path

(

const char *

str

)

Path() [4/4]

hdf5::Path::Path	(	const_iterator	first_element,
		const_iterator	last_element
	)

Warning

Should not be used, as there is no automatic sanitation. May not conform to hdf5 requirements for node names.

Member Function Documentation

absolute() [1/2]

bool hdf5::Path::absolute ( ) const

noexcept

A path is considered absolute if its first element references the root node. This is indicated by a leading / of the path string.

hdf5::Path p("/log/data");
if(p.absolute())
{
   std::cout<<"got absolute path"<<std::endl;
}

Returns

true if path is absolute, false otherwise

absolute() [2/2]

void hdf5::Path::absolute ( bool  value )

noexcept

Use this flag to set or unset the absolut flag.

Path p("data/modules");
std::cout<<p<<std::endl; // output: data/modules
p.absolute(true);
std::cout<<p<<std::endl; // output: /data/modules
p.absolute(false);
std::cout<<p<<std::endl; // output: data/modules

Parameters

value

boolean value deciding whether a path is absolute or not

append()

void hdf5::Path::append

(

const Path &

p

)

Adding path p to this instance. Basically this

hdf5::Path base_path("/entry/instrument");
hdf5::Path detector_transforms("detector/transformations");
hdf5::Path p = base_path.append(detector_transforms);
std::cout<<p<<std::endl;
//output: /entry/instrument/detector/transformations

begin()

const_iterator hdf5::Path::begin

(

)

const

Get the iterators to the beginning or the end+1 element of the path in forward direction.

Path p("/run/sensors/temperature");
std::for_each(p.begin(),p.end(),
              [](const std::string &name) { std::cout<<name<<" "; });
//output: run sensors temperature

end()

const_iterator hdf5::Path::end

(

)

const

is_name()

bool hdf5::Path::is_name

(

)

const

A path is considered to be a valid child name if list of elements equals one and the absolute path flag is not set.

Returns

true if the path is a valid child name, otherwise false

is_root()

bool hdf5::Path::is_root

(

)

const

A path is considered to reference the root group if the list of elements is empty but the absolute path flag is set.

You can construct a root path with

Path root_path("/");

or

Path root_path();
root_path.absolute(true);

though the former idiom shoud be prefered.

Returns

true if the path references the root group, false otherwise

name()

std::string hdf5::Path::name

(

)

const

The object name is the last element of a path. If the path references the root group the return value is ".".

Path p("/run/sensors/temperature");
std::cout<<p.name()<<std::endl; //output: temperature

Returns

last element of the path

operator std::string()

hdf5::Path::operator std::string ( ) const

inlineexplicit

operator+=()

Path & hdf5::Path::operator+=

(

const Path &

other

)

parent()

Path hdf5::Path::parent

(

)

const

This is basically the path with the last component stripped of. In the case that the path references the root group the parent is the root group again.

Path p("/run/sensors/temperature");
std::cout<<p.parent()<<std::endl; //output: /run/sensors

but

Path root_group("/");
std::cout<<root_group.parent()<<std::endl; //output: /

Returns

new Path instance referencing the parent path of this instance

rbegin()

const_reverse_iterator hdf5::Path::rbegin

(

)

const

rbegin() and rend() return the pair of reverse iterators for the path.

Path p("/run/sensors/temperature");
std::for_each(p.rbegin(),p.rend(),
              [](const std::string &name) { std::cout<<name<<" "; });
//output: temperature sensors run

Returns

instance of a const reverse iterator

relative_to()

Path hdf5::Path::relative_to

(

const Path &

base

)

const

rend()

const_reverse_iterator hdf5::Path::rend

(

)

const

size()

size_t hdf5::Path::size ( ) const

noexcept

Returns the number of elements in the path. In the case that the path references the root group this method will return 0.

---

The documentation for this class was generated from the following file:

• /home/p00user/src/src/h5cpp/core/path.hpp