1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10
11// <string_view>
12
13// void remove_prefix(size_type _n)
14
15#include <experimental/string_view>
16#include <cassert>
17#include <iostream>
18
19template<typename CharT>
20void test ( const CharT *s, size_t len ) {
21    typedef std::experimental::basic_string_view<CharT> SV;
22    {
23    SV sv1 ( s );
24    assert ( sv1.size() == len );
25    assert ( sv1.data() == s );
26
27    if ( len > 0 ) {
28        sv1.remove_prefix ( 1 );
29        assert ( sv1.size() == (len - 1));
30        assert ( sv1.data() == (s + 1));
31        sv1.remove_prefix ( len - 1 );
32    }
33
34    assert ( sv1.size() == 0 );
35    sv1.remove_prefix ( 0 );
36    assert ( sv1.size() == 0 );
37    }
38}
39
40#if _LIBCPP_STD_VER > 11
41constexpr size_t test_ce ( size_t n, size_t k ) {
42    typedef std::experimental::basic_string_view<char> SV;
43    SV sv1{ "ABCDEFGHIJKL", n };
44    sv1.remove_prefix ( k );
45    return sv1.size();
46}
47#endif
48
49int main () {
50    test ( "ABCDE", 5 );
51    test ( "a", 1 );
52    test ( "", 0 );
53
54    test ( L"ABCDE", 5 );
55    test ( L"a", 1 );
56    test ( L"", 0 );
57
58#if __cplusplus >= 201103L
59    test ( u"ABCDE", 5 );
60    test ( u"a", 1 );
61    test ( u"", 0 );
62
63    test ( U"ABCDE", 5 );
64    test ( U"a", 1 );
65    test ( U"", 0 );
66#endif
67
68#if _LIBCPP_STD_VER > 11
69    {
70    static_assert ( test_ce ( 5, 0 ) == 5, "" );
71    static_assert ( test_ce ( 5, 1 ) == 4, "" );
72    static_assert ( test_ce ( 5, 5 ) == 0, "" );
73    static_assert ( test_ce ( 9, 3 ) == 6, "" );
74    }
75#endif
76}
77