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HEJ 2.1.4
High energy resummation for hadron colliders
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utility.hh
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1
9#pragma once
10
11#include <array>
12#include <memory>
13#include <string>
14
15#include "boost/core/demangle.hpp"
16
17#include "fastjet/PseudoJet.hh"
18
19namespace HEJ {
20
21 inline
22 std::string join(
23 std::string const & /* delim */
24 ){
25 return "";
26 }
27
28 inline
29 std::string join(
30 std::string const & /* delim */, std::string const & str
31 ){
32 return str;
33 }
34
36
42 template<typename... Strings>
43 std::string join(
44 std::string const & delim,
45 std::string const & first, std::string const & second,
46 Strings&&... rest
47 ){
48 return join(delim, first + delim + second, std::forward<Strings>(rest)...);
49 }
50
52 template<typename T>
53 std::string type_string(T&& /*unused*/){
54 return boost::core::demangle(typeid(T).name());
55 }
56
58 template<typename... T>
59 constexpr void ignore(T&&... /*unused*/) {}
60
62 inline
63 constexpr bool nearby_ep(double a, double b, double ep){
64 assert(ep > 0);
65 return std::abs(a-b) < ep;
66 }
67
69 inline
71 fastjet::PseudoJet const & pa, fastjet::PseudoJet const & pb,
72 double ep
73 ){
74 assert(ep > 0);
75 for(size_t i = 0; i < 4; ++i){
76 if(!nearby_ep(pa[i], pb[i], ep)) return false;
77 }
78 return true;
79 }
80
81 inline
82 bool nearby(
83 fastjet::PseudoJet const & pa, fastjet::PseudoJet const & pb,
84 double const norm = 1.
85 ){
86 return nearby_ep(pa, pb, 1e-7*norm);
87 }
88
89 namespace detail {
90 template<typename T, std::size_t N, std::size_t... Ns>
91 struct ArrayTag{
92 using type = typename ArrayTag<std::array<T, N>, Ns...>::type;
93 };
94 template<typename T, std::size_t N>
95 struct ArrayTag<T, N> {
96 using type = std::array<T, N>;
97 };
98 }
99 // helper for multidimensional std::array, for example
100 // MultiArray<T, N1, N2> = std::array<std::array<T, N1>, N2>
101 template<typename T, std::size_t N, std::size_t... Ns>
102 using MultiArray = typename detail::ArrayTag<T, N, Ns...>::type;
103
104} // namespace HEJ
Main HEJ 2 Namespace.
Definition: mainpage.dox:1
constexpr void ignore(T &&...)
Eliminate compiler warnings for unused variables.
Definition: utility.hh:59
std::string type_string(T &&)
Return the name of the argument's type.
Definition: utility.hh:53
std::string join(std::string const &)
Definition: utility.hh:22
typename detail::ArrayTag< T, N, Ns... >::type MultiArray
Definition: utility.hh:102
bool nearby(fastjet::PseudoJet const &pa, fastjet::PseudoJet const &pb, double const norm=1.)
Definition: utility.hh:82
constexpr bool nearby_ep(double a, double b, double ep)
Check whether two doubles are closer than ep > 0 to each other.
Definition: utility.hh:63
std::array< T, N > type
Definition: utility.hh:96
Definition: utility.hh:91
typename ArrayTag< std::array< T, N >, Ns... >::type type
Definition: utility.hh:92