about summary refs log tree commit diff stats
path: root/html/021check_instruction.cc.html
blob: e203a3860cce87e105efd3070b943b9c199ca2a2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Mu - 021check_instruction.cc</title>
<meta name="Generator" content="Vim/7.4">
<meta name="plugin-version" content="vim7.4_v1">
<meta name="syntax" content="cpp">
<meta name="settings" content="use_css,pre_wrap,no_foldcolumn,expand_tabs,prevent_copy=">
<meta name="colorscheme" content="minimal">
<style type="text/css">
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #eeeeee; background-color: #080808; }
body { font-family: monospace; color: #eeeeee; background-color: #080808; }
* { font-size: 1.05em; }
.traceContains { color: #008000; }
.Identifier { color: #804000; }
.cSpecial { color: #008000; }
.Constant { color: #00a0a0; }
.Comment { color: #9090ff; }
.Delimiter { color: #a04060; }
.Special { color: #ff6060; }
.CommentedCode { color: #6c6c6c; }
-->
</style>

<script type='text/javascript'>
<!--

-->
</script>
</head>
<body>
<pre id='vimCodeElement'>
<span class="Comment">//: Introduce a new transform to perform various checks in instructions before</span>
<span class="Comment">//: we start running them. It'll be extensible, so that we can add checks for</span>
<span class="Comment">//: new recipes as we extend 'run' to support them.</span>
<span class="Comment">//:</span>
<span class="Comment">//: Doing checking in a separate part complicates things, because the values</span>
<span class="Comment">//: of variables in memory and the processor (current_recipe_name,</span>
<span class="Comment">//: current_instruction) aren't available at checking time. If I had a more</span>
<span class="Comment">//: sophisticated layer system I'd introduce the simpler version first and</span>
<span class="Comment">//: transform it in a separate layer or set of layers.</span>

<span class="Delimiter">:(after &quot;Transform.push_back(update_instruction_operations)&quot;)</span>
Transform<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>check_instruction<span class="Delimiter">);</span>  <span class="Comment">// idempotent</span>

<span class="Delimiter">:(code)</span>
void check_instruction<span class="Delimiter">(</span>const recipe_ordinal r<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  trace<span class="Delimiter">(</span><span class="Constant">9991</span><span class="Delimiter">,</span> <span class="Constant">&quot;transform&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;--- perform checks for recipe &quot;</span> &lt;&lt; get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name &lt;&lt; end<span class="Delimiter">();</span>
<span class="CommentedCode">//?   cerr &lt;&lt; &quot;--- perform checks for recipe &quot; &lt;&lt; get(Recipe, r).name &lt;&lt; '\n';</span>
  map&lt;string<span class="Delimiter">,</span> vector&lt;type_ordinal&gt; &gt; metadata<span class="Delimiter">;</span>
  for <span class="Delimiter">(</span>long long int i = <span class="Constant">0</span><span class="Delimiter">;</span> i &lt; SIZE<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>steps<span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span>
    instruction&amp; inst = get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>steps<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">);</span>
    if <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>is_label<span class="Delimiter">)</span> <span class="Identifier">continue</span><span class="Delimiter">;</span>
    switch <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>operation<span class="Delimiter">)</span> <span class="Delimiter">{</span>
      <span class="Comment">// Primitive Recipe Checks</span>
      case COPY: <span class="Delimiter">{</span>
        if <span class="Delimiter">(</span>SIZE<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>products<span class="Delimiter">)</span> != SIZE<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">))</span> <span class="Delimiter">{</span>
          raise_error &lt;&lt; <span class="Constant">&quot;ingredients and products should match in '&quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>to_string<span class="Delimiter">()</span> &lt;&lt; <span class="Constant">&quot;'</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
          <span class="Identifier">break</span><span class="Delimiter">;</span>
        <span class="Delimiter">}</span>
        for <span class="Delimiter">(</span>long long int i = <span class="Constant">0</span><span class="Delimiter">;</span> i &lt; SIZE<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span>
          if <span class="Delimiter">(</span>!types_match<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">),</span> inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">)))</span> <span class="Delimiter">{</span>
            raise_error &lt;&lt; maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;can't copy &quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span>original_string &lt;&lt; <span class="Constant">&quot; to &quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">).</span>original_string &lt;&lt; <span class="Constant">&quot;; types don't match</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
            <span class="Identifier">goto</span> finish_checking_instruction<span class="Delimiter">;</span>
          <span class="Delimiter">}</span>
        <span class="Delimiter">}</span>
        <span class="Identifier">break</span><span class="Delimiter">;</span>
      <span class="Delimiter">}</span>
      <span class="Comment">// End Primitive Recipe Checks</span>
      default: <span class="Delimiter">{</span>
        <span class="Comment">// Defined Recipe Checks</span>
        <span class="Comment">// End Defined Recipe Checks</span>
      <span class="Delimiter">}</span>
    <span class="Delimiter">}</span>
    finish_checking_instruction:<span class="Delimiter">;</span>
  <span class="Delimiter">}</span>
<span class="Delimiter">}</span>

<span class="Delimiter">:(scenario copy_checks_reagent_count)</span>
<span class="Special">% Hide_errors = true;</span>
recipe main [
  <span class="Constant">1</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">35</span>
]
<span class="traceContains">+error: ingredients and products should match in '1:number &lt;- copy 34, 35'</span>

<span class="Delimiter">:(scenario write_scalar_to_array_disallowed)</span>
<span class="Special">% Hide_errors = true;</span>
recipe main [
  <span class="Constant">1</span>:array:number<span class="Special"> &lt;- </span>copy <span class="Constant">34</span>
]
<span class="traceContains">+error: main: can't copy 34 to 1:array:number; types don't match</span>

<span class="Delimiter">:(scenario write_scalar_to_array_disallowed_2)</span>
<span class="Special">% Hide_errors = true;</span>
recipe main [
  <span class="Constant">1</span>:number<span class="Delimiter">,</span> <span class="Constant">2</span>:array:number<span class="Special"> &lt;- </span>copy <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">35</span>
]
<span class="traceContains">+error: main: can't copy 35 to 2:array:number; types don't match</span>

<span class="Delimiter">:(scenario write_scalar_to_address_disallowed)</span>
<span class="Special">% Hide_errors = true;</span>
recipe main [
  <span class="Constant">1</span>:address:number<span class="Special"> &lt;- </span>copy <span class="Constant">34</span>
]
<span class="traceContains">+error: main: can't copy 34 to 1:address:number; types don't match</span>

<span class="Delimiter">:(code)</span>
bool types_match<span class="Delimiter">(</span>reagent lhs<span class="Delimiter">,</span> reagent rhs<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  <span class="Comment">// '_' never raises type error</span>
  if <span class="Delimiter">(</span>is_dummy<span class="Delimiter">(</span>lhs<span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">true</span><span class="Delimiter">;</span>
  <span class="Comment">// to sidestep type-checking, use /raw in the source.</span>
  <span class="Comment">// this is unsafe, and will be highlighted in red inside vim. just for some tests.</span>
  if <span class="Delimiter">(</span>is_raw<span class="Delimiter">(</span>rhs<span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">true</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>is_literal<span class="Delimiter">(</span>rhs<span class="Delimiter">))</span> <span class="Identifier">return</span> valid_type_for_literal<span class="Delimiter">(</span>lhs<span class="Delimiter">,</span> rhs<span class="Delimiter">)</span> &amp;&amp; size_of<span class="Delimiter">(</span>rhs<span class="Delimiter">)</span> == size_of<span class="Delimiter">(</span>lhs<span class="Delimiter">);</span>
  if <span class="Delimiter">(</span>!lhs<span class="Delimiter">.</span>type<span class="Delimiter">)</span> <span class="Identifier">return</span> !rhs<span class="Delimiter">.</span>type<span class="Delimiter">;</span>
  <span class="Identifier">return</span> types_match<span class="Delimiter">(</span>lhs<span class="Delimiter">.</span>type<span class="Delimiter">,</span> rhs<span class="Delimiter">.</span>type<span class="Delimiter">);</span>
<span class="Delimiter">}</span>

bool valid_type_for_literal<span class="Delimiter">(</span>const reagent&amp; lhs<span class="Delimiter">,</span> const reagent&amp; literal_rhs<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  if <span class="Delimiter">(</span>is_mu_array<span class="Delimiter">(</span>lhs<span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  <span class="Comment">// End valid_type_for_literal Special-cases</span>
  <span class="Comment">// allow writing 0 to any address</span>
  if <span class="Delimiter">(</span>is_mu_address<span class="Delimiter">(</span>lhs<span class="Delimiter">))</span> <span class="Identifier">return</span> literal_rhs<span class="Delimiter">.</span>name == <span class="Constant">&quot;0&quot;</span><span class="Delimiter">;</span>
  <span class="Identifier">return</span> <span class="Constant">true</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>

<span class="Comment">// two types match if the second begins like the first</span>
<span class="Comment">// (trees perform the same check recursively on each subtree)</span>
bool types_match<span class="Delimiter">(</span>type_tree* lhs<span class="Delimiter">,</span> type_tree* rhs<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  if <span class="Delimiter">(</span>!lhs<span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">true</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>!rhs || rhs<span class="Delimiter">-&gt;</span>value == <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
    if <span class="Delimiter">(</span>lhs<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;array&quot;</span><span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
    if <span class="Delimiter">(</span>lhs<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;address&quot;</span><span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
    <span class="Identifier">return</span> size_of<span class="Delimiter">(</span>rhs<span class="Delimiter">)</span> == size_of<span class="Delimiter">(</span>lhs<span class="Delimiter">);</span>
  <span class="Delimiter">}</span>
  if <span class="Delimiter">(</span>lhs<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;character&quot;</span><span class="Delimiter">)</span> &amp;&amp; rhs<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;number&quot;</span><span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">true</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>lhs<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;number&quot;</span><span class="Delimiter">)</span> &amp;&amp; rhs<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;character&quot;</span><span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">true</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>lhs<span class="Delimiter">-&gt;</span>value != rhs<span class="Delimiter">-&gt;</span>value<span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  <span class="Identifier">return</span> types_match<span class="Delimiter">(</span>lhs<span class="Delimiter">-&gt;</span>left<span class="Delimiter">,</span> rhs<span class="Delimiter">-&gt;</span>left<span class="Delimiter">)</span> &amp;&amp; types_match<span class="Delimiter">(</span>lhs<span class="Delimiter">-&gt;</span>right<span class="Delimiter">,</span> rhs<span class="Delimiter">-&gt;</span>right<span class="Delimiter">);</span>
<span class="Delimiter">}</span>

<span class="Comment">// hacky version that allows 0 addresses</span>
bool types_match<span class="Delimiter">(</span>const reagent lhs<span class="Delimiter">,</span> const type_tree* rhs<span class="Delimiter">,</span> const vector&lt;double&gt;&amp; data<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  if <span class="Delimiter">(</span>is_dummy<span class="Delimiter">(</span>lhs<span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">true</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>rhs<span class="Delimiter">-&gt;</span>value == <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
    if <span class="Delimiter">(</span>lhs<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;array&quot;</span><span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
    if <span class="Delimiter">(</span>lhs<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;address&quot;</span><span class="Delimiter">))</span> <span class="Identifier">return</span> scalar<span class="Delimiter">(</span>data<span class="Delimiter">)</span> &amp;&amp; data<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)</span> == <span class="Constant">0</span><span class="Delimiter">;</span>
    <span class="Identifier">return</span> size_of<span class="Delimiter">(</span>rhs<span class="Delimiter">)</span> == size_of<span class="Delimiter">(</span>lhs<span class="Delimiter">);</span>
  <span class="Delimiter">}</span>
  if <span class="Delimiter">(</span>lhs<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>value != rhs<span class="Delimiter">-&gt;</span>value<span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  <span class="Identifier">return</span> types_match<span class="Delimiter">(</span>lhs<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>left<span class="Delimiter">,</span> rhs<span class="Delimiter">-&gt;</span>left<span class="Delimiter">)</span> &amp;&amp; types_match<span class="Delimiter">(</span>lhs<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">,</span> rhs<span class="Delimiter">-&gt;</span>right<span class="Delimiter">);</span>
<span class="Delimiter">}</span>

bool is_raw<span class="Delimiter">(</span>const reagent&amp; r<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  <span class="Identifier">return</span> has_property<span class="Delimiter">(</span>r<span class="Delimiter">,</span> <span class="Constant">&quot;raw&quot;</span><span class="Delimiter">);</span>
<span class="Delimiter">}</span>

bool is_mu_array<span class="Delimiter">(</span>reagent r<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  if <span class="Delimiter">(</span>!r<span class="Delimiter">.</span>type<span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>is_literal<span class="Delimiter">(</span>r<span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  <span class="Identifier">return</span> r<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;array&quot;</span><span class="Delimiter">);</span>
<span class="Delimiter">}</span>

bool is_mu_address<span class="Delimiter">(</span>reagent r<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  if <span class="Delimiter">(</span>!r<span class="Delimiter">.</span>type<span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>is_literal<span class="Delimiter">(</span>r<span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  <span class="Identifier">return</span> r<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;address&quot;</span><span class="Delimiter">);</span>
<span class="Delimiter">}</span>

bool is_mu_number<span class="Delimiter">(</span>reagent r<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  if <span class="Delimiter">(</span>!r<span class="Delimiter">.</span>type<span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>is_literal<span class="Delimiter">(</span>r<span class="Delimiter">))</span>
    <span class="Identifier">return</span> r<span class="Delimiter">.</span>properties<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>second<span class="Delimiter">-&gt;</span>value == <span class="Constant">&quot;literal-number&quot;</span>
        || r<span class="Delimiter">.</span>properties<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>second<span class="Delimiter">-&gt;</span>value == <span class="Constant">&quot;literal&quot;</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>r<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;character&quot;</span><span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">true</span><span class="Delimiter">;</span>  <span class="Comment">// permit arithmetic on unicode code points</span>
  <span class="Identifier">return</span> r<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;number&quot;</span><span class="Delimiter">);</span>
<span class="Delimiter">}</span>

bool is_mu_scalar<span class="Delimiter">(</span>reagent r<span class="Delimiter">)</span> <span class="Delimiter">{</span>
  if <span class="Delimiter">(</span>!r<span class="Delimiter">.</span>type<span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>is_literal<span class="Delimiter">(</span>r<span class="Delimiter">))</span>
    <span class="Identifier">return</span> !r<span class="Delimiter">.</span>properties<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>second || r<span class="Delimiter">.</span>properties<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>second<span class="Delimiter">-&gt;</span>value != <span class="Constant">&quot;literal-string&quot;</span><span class="Delimiter">;</span>
  if <span class="Delimiter">(</span>is_mu_array<span class="Delimiter">(</span>r<span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
  <span class="Identifier">return</span> size_of<span class="Delimiter">(</span>r<span class="Delimiter">)</span> == <span class="Constant">1</span><span class="Delimiter">;</span>
<span class="Delimiter">}</span>
</pre>
</body>
</html>
<!-- vim: set foldmethod=manual : -->