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| '''C++ Technical Report 1 (TR1)''' is the common name for '''''ISO/IEC TR 19768, C++ Library Extensions''''', which was a document proposing additions to the [[C++ standard library]] for the C++03 language standard. The additions include [[regular expression]]s, [[smart pointer]]s, [[hash table]]s, and [[random number generator]]s. TR1 was not a standard itself, but rather a draft document. However, most of its proposals became part of the current official standard, [[C++11]]. Before C++11 was standardized, vendors used this document as a guide to create extensions. The report's goal was "to build more widespread existing practice for an expanded C++ standard library."
| | I am Oscar and I totally dig that name. Hiring has been my profession for some time but I've already applied for an additional one. His wife doesn't like it the way he does but what he really likes doing is to do aerobics and he's been performing it for quite a whilst. For a while she's been in South Dakota.<br><br>Feel free to surf to my website [http://jewelrycase.co.kr/xe/Ring/11593 at home std testing] |
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| The report was first circulated in draft form in 2005 as [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1836.pdf Draft Technical Report on C++ Library Extensions], then published in 2007 as an ISO/IEC standard as [http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?ics1=35&ics2=60&ics3=&csnumber=43289 ISO/IEC TR 19768:2007].
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| ==Overview==
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| [[Compilers]] needed not include the TR1 components to be conforming to the C++ standard, because TR1 proposals were not part of the standard itself, but only a set of possible additions that were still to be ratified. However, most of it was available from [[Boost C++ Libraries|Boost]], and several compiler/library distributors implemented all or part of the components. TR1 was not a complete list of additions to the library that were going to appear in the next standard, [[C++11]]. For example, C++11 includes thread support library that is not available in TR1.
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| The new components were defined in the <code>std::tr1</code> [[namespace]] to distinguish them from the then current standard library.
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| There is also a second technical report, [[#Technical Report 2|C++ Technical Report 2]], planned for publishing after C++11 [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1810.html].
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| ==Components==
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| TR1 includes the following components:
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| ===General utilities===
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| '''Reference wrapper''' – enables passing [[Reference#Computer science|references]], rather than copies, into algorithms or function objects. The feature was based on Boost.Ref.<ref>[http://www.boost.org/doc/html/ref.html Chapter 22. Boost.Ref – Boost 1.48.0<!-- Bot generated title -->]</ref> A [[Adapter pattern|wrapper]] reference is obtained from an instance of the template class <code>reference_wrapper</code>. Wrapper references are similar to normal references (‘&’) of the C++ language. To obtain a wrapper reference from any object the template class <code>ref</code> is used (for a constant reference <code>cref</code> is used).
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| Wrapper references are useful above all for template functions, when argument deduction would not deduce a reference (e.g. when forwarding arguments):
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| <source lang="cpp">
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| #include <iostream>
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| #include <tr1/functional>
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| void f( int &r ) { ++r; }
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| template< class Funct, class Arg >
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| void g( Funct f, Arg t )
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| {
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| f(t);
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| }
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| int main()
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| {
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| int i = 0;
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| g( f, i ); // 'g< void(int &r), int >' is instantiated
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| std::cout << i << "\n"; // Output: 0
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| g( f, std::tr1::ref(i) ); // 'g< void(int &r), reference_wrapper<int> >' is instanced
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| std::cout << i << "\n"; // Output: 1
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| }
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| </source>
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| '''Smart pointers''' – adds several classes that simplify object lifetime management in complex cases. Three main classes are added:
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| *<code>shared_ptr</code> – a reference-counted smart pointer
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| *<code>weak_ptr</code> – a variant of <code>shared_ptr</code> that doesn't increase the reference count
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| The proposal is based on Boost Smart Pointer library <ref>[http://www.boost.org/libs/smart_ptr/smart_ptr.htm Smart Pointers – Boost 1.48.0<!-- Bot generated title -->]</ref>
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| ===Function objects===
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| These four modules are added to the <code><functional></code> header file:
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| '''Polymorphic function wrapper''' (<code>function</code>) – can store any callable function (function pointers, member function pointers, and function objects) that uses a specified function call signature. The type does not depend on the kind of the callable used. Based on Boost.Function <ref>[http://www.boost.org/doc/html/function.html Chapter 9. Boost.Function – Boost 1.48.0<!-- Bot generated title -->]</ref>
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| '''Function object binders''' (<code>bind</code>) – can bind any parameter [[Parameter#Computer science|parameters]] to function objects. Function composition is also allowed. This is a generalized version of the standard <code>std::bind1st</code> and <code>std::bind2nd</code> bind functions. The feature is based on Boost Bind library.<ref>[http://www.boost.org/libs/bind/bind.html Boost: bind.hpp documentation – Boost 1.48.0<!-- Bot generated title -->]</ref>
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| '''Function return types''' (<code>result_of</code>) – determines the type of a call expression. | |
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| '''<code>mem_fn</code>''' – enhancement to the standard <code>std::mem_fun</code> and <code>std::mem_fun_ref</code>. Allows [[pointer (computer programming)|pointer]]s to member [[Subroutine|functions]] to be treated as function objects. Based on Boost Mem Fn library <ref>[http://www.boost.org/libs/bind/mem_fn.html Boost: mem_fn.hpp documentation – Boost 1.48.0<!-- Bot generated title -->]</ref>
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| ===Metaprogramming and type traits===
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| There is now <code><type_traits></code> header file that contains many useful trait meta-templates, such as <code>is_pod</code>, <code>has_virtual_destructor</code>, <code>remove_extent</code>, etc. It facilitates metaprogramming by enabling queries on and transformation between different [[Datatype|types]] The proposal is based on Boost Type Traits library [http://www.boost.org/doc/libs/1_37_0/libs/type_traits/doc/html/index.html].
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| ===Numerical facilities===
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| ====Random number generation====
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| * new <code><random></code> header file – <code>variate_generator</code>, <code>[[Mersenne Twister|mersenne_twister]]</code>, <code>[[Poisson Distribution|poisson_distribution]]</code>, etc.
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| * utilities for generating random numbers using any of several [[Pseudorandom number generators]], engines, and [[probability distributions]] <!-- I have suspicion this comes from Boost too --><!-- nope! Boost and TR1 facilities come from Fermilab -->
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| ====Mathematical special functions====
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| '''Some features of TR1, such as the mathematical special functions and certain C99 additions, are not included in the Visual C++ implementation of TR1.'''
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| The Mathematical special functions library was not standardized in C++11.
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| * additions to the <code><cmath></code>/<code><math.h></code> header files – <code>[[Beta function|beta]]</code>, <code>[[Legendre polynomials|legendre]]</code>, etc. <!-- these come from Fermilab, too -->
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| These functions will likely be of principal interest to programmers in the engineering and scientific disciplines.
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| The following table shows all 23 special functions described in TR1.
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| {| class="wikitable"
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| |-
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| ! Function name !! Function prototype !! Mathematical expression
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| |-
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| ! [[Associated Laguerre polynomials]]
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| | double '''assoc_laguerre'''( unsigned n, unsigned m, double x ) ; || <math>{L_n}^m(x) = (-1)^m \frac{d^m}{dx^m} L_{n+m}(x), \text{ for } x \ge 0</math>
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| |-
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| ! [[Associated Legendre polynomials]]
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| | double '''assoc_legendre'''( unsigned l, unsigned m, double x ) ; || <math>{P_l}^m(x) = (1-x^2)^{m/2} \frac{d^m}{dx^m} P_l(x), \text{ for } x \ge 0</math>
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| |-
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| ! [[Beta function]]
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| | double '''beta'''( double x, double y ) ; || <math>\Beta(x,y)=\frac{\Gamma(x) \Gamma(y)}{\Gamma(x+y)}</math>
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| |-
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| ! [[Complete elliptic integral of the first kind]]
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| | double '''comp_ellint_1'''( double k ) ; || <math>K(k) = F\left(k, \textstyle \frac{\pi}{2}\right) = \int_0^{\frac{\pi}{2}} \frac{d\theta}{\sqrt{1 - k^2 \sin^2 \theta}}</math>
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| |-
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| ! [[Complete elliptic integral of the second kind]]
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| | double '''comp_ellint_2'''( double k ) ; || <math>E\left(k, \textstyle \frac{\pi}{2}\right) = \int_0^{\frac{\pi}{2}} \sqrt{1 - k^2 \sin^2 \theta}\; d\theta</math>
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| |-
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| ! [[Complete elliptic integral of the third kind]]
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| | double '''comp_ellint_3'''( double k, double nu ) ; || <math>\Pi\left(\nu, k, \textstyle \frac{\pi}{2}\right) = \int_0^{\frac{\pi}{2}} \frac{d\theta}{(1 - \nu \sin^2 \theta)\sqrt{1 - k^2 \sin^2 \theta}}</math>
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| |-
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| ! [[Confluent hypergeometric functions]]
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| | double '''conf_hyperg'''( double a, double c, double x ) ; || <math>F(a, c, x) = \frac{\Gamma(c)}{\Gamma(a)} \sum_{n = 0}^\infty \frac{\Gamma(a + n) x^n}{\Gamma(c + n) n!}</math>
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| |-
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| ! [[Regular modified cylindrical Bessel functions]]
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| | double '''cyl_bessel_i'''( double nu, double x ) ; || <math>I_\nu(x) = i^{-\nu} J_\nu(ix) = \sum_{k = 0}^\infty \frac{(x/2)^{\nu + 2k}}{k! \; \Gamma(\nu + k + 1)}, \text{ for } x \ge 0</math>
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| |-
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| ! [[Cylindrical Bessel functions of the first kind]]
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| | double '''cyl_bessel_j'''( double nu, double x ) ; || <math>J_\nu(x) = \sum_{k = 0}^\infty \frac{(-1)^k \; (x/2)^{\nu + 2k}}{k! \; \Gamma(\nu + k + 1)}, \text{ for } x \ge 0</math>
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| |-
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| ! [[Irregular modified cylindrical Bessel functions]]
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| | double '''cyl_bessel_k'''( double nu, double x ) ; || <math>\begin{align}
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| K_\nu(x) & = \textstyle\frac{\pi}{2} i^{\nu+1} \big(J_\nu(ix) + i N_\nu(ix)\big) \\
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| & = \begin{cases}
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| \displaystyle \frac{I_{-\nu}(x) - I_\nu(x)}{\sin \nu\pi}, & \text{for } x \ge 0 \text{ and } \nu \notin \mathbb{Z} \\[10pt]
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| \displaystyle \frac{\pi}{2} \lim_{\mu \to \nu} \frac{I_{-\mu}(x) - I_\mu(x)}{\sin \mu\pi}, & \text{for } x < 0 \text{ and } \nu \in \mathbb{Z} \\
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| \end{cases}
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| \end{align}</math>
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| |-
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| ! [[Cylindrical Neumann functions]]
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| [[Cylindrical Bessel functions of the second kind]]
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| | double '''cyl_neumann'''( double nu, double x ) ; || <math>
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| N_\nu(x) = \begin{cases}
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| \displaystyle \frac{J_\nu(x)\cos \nu\pi - J_{-\nu}(x)}{\sin \nu\pi}, & \text{for } x \ge 0 \text{ and } \nu \notin \mathbb{Z} \\[10pt]
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| \displaystyle \lim_{\mu \to \nu} \frac{J_\mu(x)\cos \mu\pi - J_{-\mu}(x)}{\sin \mu\pi}, & \text{for } x < 0 \text{ and } \nu \in \mathbb{Z} \\
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| \end{cases}
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| </math>
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| |-
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| ! [[Incomplete elliptic integral of the first kind]]
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| | double '''ellint_1'''( double k, double phi ) ; || <math>F(k,\phi)=\int_0^\phi\frac{d\theta}{\sqrt{1-k^2\sin^2\theta}}, \text{ for } \left|k\right| \le 1</math>
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| |-
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| ! [[Incomplete elliptic integral of the second kind]]
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| | double '''ellint_2'''( double k, double phi ) ; || <math>\displaystyle E(k,\phi)=\int_0^\phi\sqrt{1-k^2\sin^2\theta}d\theta, \text{ for } \left|k\right| \le 1</math>
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| |-
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| ! [[Incomplete elliptic integral of the third kind]]
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| | double '''ellint_3'''( double k, double nu, double phi ) ; || <math>\Pi(k,\nu,\phi)=\int_0^\phi\frac{d\theta}{\left(1-\nu\sin^2\theta\right)\sqrt{1-k^2\sin^2\theta}}, \text{ for } \left|k\right| \le 1</math>
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| |-
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| ! [[Exponential integral]]
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| | double '''expint'''( double x ) ; || <math> \mbox{E}i(x)=-\int_{-x}^{\infty} \frac{e^{-t}}{t}\, dt</math>
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| |-
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| ! [[Hermite polynomials]]
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| | double '''hermite'''( unsigned n, double x ) ; || <math>H_n(x)=(-1)^n e^{x^2}\frac{d^n}{dx^n}e^{-x^2}\,\!</math>
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| |-
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| ! [[Hypergeometric series]]
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| | double '''hyperg'''( double a, double b, double c, double x ) ; || <math>F(a,b,c,x)=\frac{\Gamma(c)}{\Gamma(a)\Gamma(b)}\sum_{n = 0}^\infty\frac{\Gamma(a+n)\Gamma(b+n)}{\Gamma(c+n)}\frac{x^n}{n!}</math>
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| |-
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| ! [[Laguerre polynomials]]
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| | double '''laguerre'''( unsigned n, double x ) ; || <math>L_n(x)=\frac{e^x}{n!}\frac{d^n}{dx^n}\left(x^n e^{-x}\right), \text{ for } x \ge 0</math>
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| |-
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| ! [[Legendre polynomials]]
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| | double '''legendre'''( unsigned l, double x ) ; || <math>P_l(x) = {1 \over 2^l l!} {d^l \over dx^l } (x^2 -1)^l, \text{ for } \left|x\right| \le 1 </math>
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| |-
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| ! [[Riemann zeta function]]
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| | double '''riemann_zeta'''( double x ) ; || <math>
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| \Zeta(x) =
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| \begin{cases}
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| \displaystyle \sum_{k = 1}^\infty k^{-x}, & \text{for } x > 1 \\[10pt]
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| \displaystyle 2^x\pi^{x-1}\sin\left(\frac{x\pi}{2}\right)\Gamma(1-x)\zeta(1-x), & \text{for } x < 1 \\
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| \end{cases}
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| </math>
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| |-
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| ! [[Spherical Bessel functions of the first kind]]
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| | double '''sph_bessel'''( unsigned n, double x ) ; || <math>j_n(x) = \sqrt{\frac{\pi}{2x}} J_{n+1/2}(x), \text{ for } x \ge 0</math>
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| |-
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| ! [[Spherical associated Legendre functions]]
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| | double '''sph_legendre'''( unsigned l, unsigned m, double theta ) ; || <math> Y_{l}^{m}(\theta, 0) \text{ where } Y_{l}^{m}(\theta, \phi) = (-1)^{m}\left[\frac{(2l+1)}{4\pi}\frac{(l-m)!}{(l+m)!}\right]^{1 \over 2} P_{l}^{m}(\cos \theta)e^{\mathrm{i}m\phi}, \text{ for } |m| \leq l</math>
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| |-
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| ! [[Spherical Neumann functions]]
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| [[Spherical Bessel functions of the second kind]]
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| | double '''sph_neumann'''( unsigned n, double x ) ; || <math>n_n(x) = \left(\frac{\pi}{2x}\right)^{\frac{1}{2}}N_{n+\frac{1}{2}}(x), \text{ for } x \ge 0</math>
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| |}
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| Each function has two additional variants. Appending the suffix ‘'''f'''’ or ‘'''l'''’ to a function name gives a function that operates on <code>float</code> or <code>long double</code> values respectively. For example:
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| <source lang="cpp">
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| float sph_neumannf( unsigned n, float x ) ;
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| long double sph_neumannl( unsigned n, long double x ) ;
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| </source>
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| ===Containers===
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| ====Tuple types====
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| * new <code><tuple></code> header file – <code>tuple</code>
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| * based on Boost Tuple library <ref>[http://www.boost.org/libs/tuple/doc/tuple_users_guide.html The Boost Tuple Library – Boost 1.48.0<!-- Bot generated title -->]</ref>
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| * vaguely an extension of the standard <code>std::pair</code>
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| * fixed size collection of elements, which may be of different [[Datatype|types]]
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| ====Fixed size array====
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| * new <code><array></code> header file – <code>array</code>
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| * taken from Boost Array library <ref>[http://www.boost.org/doc/html/array.html Chapter 3. Boost.Array – Boost 1.48.0<!-- Bot generated title -->]</ref>
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| * as opposed to dynamic array types such as the standard <code>std::vector</code>
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| ====Hash tables====
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| * new <code><unordered_set></code>, <code><[[unordered map (C++)|unordered_map]]></code> header files
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| * they implement the <code>unordered_set</code>, <code>unordered_multiset</code>, <code>unordered_map</code>, and <code>unordered_multimap</code> classes, analogous to <code>set</code>, <code>multiset</code>, <code>map</code>, and <code>multimap</code>, respectively
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| ** unfortunately, <code>unordered_set</code> and <code>unordered_multiset</code> cannot be used with the <code>set_union</code>, <code>set_intersection</code>, <code>set_difference</code>, <code>set_symmetric_difference</code>, and <code>includes</code> standard library functions, which work for <code>set</code> and <code>multiset</code>
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| * new implementation, not derived from an existing library, not fully API compatible with existing libraries
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| * like all [[hash table]]s, often provide [[Algorithmic complexity|constant time]] lookup of elements but the worst case can be linear in the size of the container
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| ===Regular expressions===
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| * new <code><regex></code> header file – <code>regex</code>, <code>regex_match</code>, <code>regex_search</code>, <code>regex_replace</code>, etc.
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| * based on Boost RegEx library <ref>[http://www.boost.org/doc/libs/1_36_0/libs/regex/doc/html/index.html Boost.Regex – Boost 1.36.0<!-- Bot generated title -->]</ref>
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| * pattern matching library
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| ===C compatibility===
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| [[C++]] is designed to be compatible with the [[C (programming language)|C programming language]], but is not a strict superset of C due to diverging standards. TR1 attempts to reconcile some of these differences through additions to various headers in the C++ library, such as <complex>, <locale>, <cmath>, etc. These changes help to bring C++ more in line with the [[C (programming language)#C99|C99]] version of the C standard (not all parts of C99 are included in TR1).
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| ==Technical Report 2==
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| In 2005 a request for proposals for a TR2 was made with a special interest in Unicode, XML/HTML, Networking and usability for novice programmers.[http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1810.html].
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| Some of the proposals include:
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| * Threads [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1883.pdf]
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| * The [[Asio C++ library]] (networking [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1925.pdf][http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2175.pdf]).
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| * Signals/Slots [http://www.mail-archive.com/libsigc-list@gnome.org/msg00115.html][http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2086.pdf]
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| * Filesystem Library [http://www.open-std.org/JTC1/sc22/WG21/docs/papers/2011/n3239.html] – Based on the Boost Filesystem Library, for query/manipulation of paths, files and directories.
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| * Boost Any Library [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1939.html]
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| * Lexical Conversion Library [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1973.html]
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| * New String Algorithms [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2059.html#abstract]
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| * Toward a More Complete Taxonomy of Algebraic Properties for Numeric Libraries in TR2 [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/]
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| * Adding heterogeneous comparison lookup to associative containers for TR2 [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2882.pdf]
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| ==See also==
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| *[[C++11]], the most recent standard for the C++ programming language; the library improvements were based on TR1
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| *[[C11 (C standard revision)]], the most recent standard for the C programming language
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| *[[Boost library]], a large collection of portable C++ libraries, several of which were included in TR1
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| *[[Standard Template Library]], part of the current C++ Standard Library
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| ==Notes==
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| {{reflist}}
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| ==References==
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| *{{cite journal | title = Draft Technical Report on C++ Library Extensions | url = http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1836.pdf | date = 2005-06-24 | format = PDF | last = ISO/IEC JTC1/SC22/WG21}}
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| * {{cite web |title=ISO/IEC TR 19768:2007 |url=http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?ics1=35&ics2=60&ics3=&csnumber=43289 }}
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| *{{cite book | first = Peter | last = Becker | title = The C++ Standard Library Extensions: A Tutorial and Reference | year = 2006 | publisher = Addison-Wesley Professional | isbn = 0-321-41299-0}}
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| ==External links==
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| *[http://aristeia.com/EC3E/TR1_info_frames.html Scott Meyers' Effective C++: TR1 Information] – contains links to the TR1 proposal documents which provide background and rationale for the TR1 libraries.
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| [[Category:C++ Standard Library]]
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