diff options
Diffstat (limited to 'html/subx/001help.cc.html')
| -rw-r--r-- | html/subx/001help.cc.html | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/html/subx/001help.cc.html b/html/subx/001help.cc.html new file mode 100644 index 00000000..73ad6bfb --- /dev/null +++ b/html/subx/001help.cc.html @@ -0,0 +1,275 @@ +<!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 - subx/001help.cc</title> +<meta name="Generator" content="Vim/7.4"> +<meta name="plugin-version" content="vim7.4_v2"> +<meta name="syntax" content="cpp"> +<meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy="> +<meta name="colorscheme" content="minimal"> +<style type="text/css"> +<!-- +pre { white-space: pre-wrap; font-family: monospace; color: #aaaaaa; background-color: #080808; } +body { font-size: 12pt; font-family: monospace; color: #aaaaaa; background-color: #080808; } +a { color:#eeeeee; text-decoration: none; } +a:hover { text-decoration: underline; } +* { font-size: 12pt; font-size: 1em; } +.Constant { color: #00a0a0; } +.Conceal { color: #4e4e4e; } +.SalientComment { color: #00ffff; } +.Comment { color: #9090ff; } +.Comment a { color:#0000ee; text-decoration:underline; } +.Delimiter { color: #800080; } +.LineNr { color: #444444; } +.Identifier { color: #c0a020; } +.Normal { color: #aaaaaa; background-color: #080808; padding-bottom: 1px; } +.PreProc { color: #800080; } +.CommentedCode { color: #6c6c6c; } +.cSpecial { color: #008000; } +--> +</style> + +<script type='text/javascript'> +<!-- + +/* function to open any folds containing a jumped-to line before jumping to it */ +function JumpToLine() +{ + var lineNum; + lineNum = window.location.hash; + lineNum = lineNum.substr(1); /* strip off '#' */ + + if (lineNum.indexOf('L') == -1) { + lineNum = 'L'+lineNum; + } + lineElem = document.getElementById(lineNum); + /* Always jump to new location even if the line was hidden inside a fold, or + * we corrected the raw number to a line ID. + */ + if (lineElem) { + lineElem.scrollIntoView(true); + } + return true; +} +if ('onhashchange' in window) { + window.onhashchange = JumpToLine; +} + +--> +</script> +</head> +<body onload='JumpToLine();'> +<pre id='vimCodeElement'> +<span id="L1" class="LineNr"> 1 </span><span class="Comment">//: Everything this project/binary supports.</span> +<span id="L2" class="LineNr"> 2 </span><span class="Comment">//: This should give you a sense for what to look forward to in later layers.</span> +<span id="L3" class="LineNr"> 3 </span> +<span id="L4" class="LineNr"> 4 </span><span class="Delimiter">:(before "End Commandline Parsing")</span> +<span id="L5" class="LineNr"> 5 </span><span class="Normal">if</span> <span class="Delimiter">(</span>argc <= <span class="Constant">1</span> || is_equal<span class="Delimiter">(</span>argv[<span class="Constant">1</span>]<span class="Delimiter">,</span> <span class="Constant">"--help"</span><span class="Delimiter">))</span> <span class="Delimiter">{</span> +<span id="L6" class="LineNr"> 6 </span> <span class="Comment">//: this is the functionality later layers will provide</span> +<span id="L7" class="LineNr"> 7 </span> <span class="Comment">// currently no automated tests for commandline arg parsing</span> +<span id="L8" class="LineNr"> 8 </span> cerr << <span class="Constant">"Usage:</span><span class="cSpecial">\n</span><span class="Constant">"</span> +<span id="L9" class="LineNr"> 9 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Conceal">¦</span><< <span class="Constant">" subx test</span><span class="cSpecial">\n</span><span class="Constant">"</span><span class="Delimiter">;</span> +<span id="L10" class="LineNr"> 10 </span> <span class="Identifier">return</span> <span class="Constant">0</span><span class="Delimiter">;</span> +<span id="L11" class="LineNr"> 11 </span><span class="Delimiter">}</span> +<span id="L12" class="LineNr"> 12 </span> +<span id="L13" class="LineNr"> 13 </span><span class="SalientComment">//:: Helper function used by the above fragment of code (and later layers too,</span> +<span id="L14" class="LineNr"> 14 </span><span class="SalientComment">//:: who knows?).</span> +<span id="L15" class="LineNr"> 15 </span><span class="Comment">//: The :(code) directive appends function definitions to the end of the</span> +<span id="L16" class="LineNr"> 16 </span><span class="Comment">//: project. Regardless of where functions are defined, we can call them</span> +<span id="L17" class="LineNr"> 17 </span><span class="Comment">//: anywhere we like as long as we format the function header in a specific</span> +<span id="L18" class="LineNr"> 18 </span><span class="Comment">//: way: put it all on a single line without indent, end the line with ') {'</span> +<span id="L19" class="LineNr"> 19 </span><span class="Comment">//: and no trailing whitespace. As long as functions uniformly start this</span> +<span id="L20" class="LineNr"> 20 </span><span class="Comment">//: way, our 'build' script contains a little command to automatically</span> +<span id="L21" class="LineNr"> 21 </span><span class="Comment">//: generate declarations for them.</span> +<span id="L22" class="LineNr"> 22 </span><span class="Delimiter">:(code)</span> +<span id="L23" class="LineNr"> 23 </span><span class="Normal">bool</span> is_equal<span class="Delimiter">(</span><span class="Normal">char</span>* s<span class="Delimiter">,</span> <span class="Normal">const</span> <span class="Normal">char</span>* lit<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L24" class="LineNr"> 24 </span> <span class="Identifier">return</span> strncmp<span class="Delimiter">(</span>s<span class="Delimiter">,</span> lit<span class="Delimiter">,</span> strlen<span class="Delimiter">(</span>lit<span class="Delimiter">))</span> == <span class="Constant">0</span><span class="Delimiter">;</span> +<span id="L25" class="LineNr"> 25 </span><span class="Delimiter">}</span> +<span id="L26" class="LineNr"> 26 </span> +<span id="L27" class="LineNr"> 27 </span><span class="Normal">bool</span> starts_with<span class="Delimiter">(</span><span class="Normal">const</span> string& s<span class="Delimiter">,</span> <span class="Normal">const</span> string& pat<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L28" class="LineNr"> 28 </span> string::const_iterator a=s<span class="Delimiter">.</span>begin<span class="Delimiter">(),</span> b=pat<span class="Delimiter">.</span>begin<span class="Delimiter">();</span> +<span id="L29" class="LineNr"> 29 </span> <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Comment">/*</span><span class="Comment">nada</span><span class="Comment">*/</span><span class="Delimiter">;</span> a!=s<span class="Delimiter">.</span>end<span class="Delimiter">()</span> && b!=pat<span class="Delimiter">.</span>end<span class="Delimiter">();</span> ++a<span class="Delimiter">,</span> ++b<span class="Delimiter">)</span> +<span id="L30" class="LineNr"> 30 </span> <span class="Conceal">¦</span> <span class="Normal">if</span> <span class="Delimiter">(</span>*a != *b<span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span> +<span id="L31" class="LineNr"> 31 </span> <span class="Identifier">return</span> b == pat<span class="Delimiter">.</span>end<span class="Delimiter">();</span> +<span id="L32" class="LineNr"> 32 </span><span class="Delimiter">}</span> +<span id="L33" class="LineNr"> 33 </span> +<span id="L34" class="LineNr"> 34 </span><span class="Comment">//: I'll throw some style conventions here for want of a better place for them.</span> +<span id="L35" class="LineNr"> 35 </span><span class="Comment">//: As a rule I hate style guides. Do what you want, that's my motto. But since</span> +<span id="L36" class="LineNr"> 36 </span><span class="Comment">//: we're dealing with C/C++, the one big thing we want to avoid is undefined</span> +<span id="L37" class="LineNr"> 37 </span><span class="Comment">//: behavior. If a compiler ever encounters undefined behavior it can make</span> +<span id="L38" class="LineNr"> 38 </span><span class="Comment">//: your program do anything it wants.</span> +<span id="L39" class="LineNr"> 39 </span><span class="Comment">//:</span> +<span id="L40" class="LineNr"> 40 </span><span class="Comment">//: For reference, my checklist of undefined behaviors to watch out for:</span> +<span id="L41" class="LineNr"> 41 </span><span class="Comment">//: out-of-bounds access</span> +<span id="L42" class="LineNr"> 42 </span><span class="Comment">//: uninitialized variables</span> +<span id="L43" class="LineNr"> 43 </span><span class="Comment">//: use after free</span> +<span id="L44" class="LineNr"> 44 </span><span class="Comment">//: dereferencing invalid pointers: null, a new of size 0, others</span> +<span id="L45" class="LineNr"> 45 </span><span class="Comment">//:</span> +<span id="L46" class="LineNr"> 46 </span><span class="Comment">//: casting a large number to a type too small to hold it</span> +<span id="L47" class="LineNr"> 47 </span><span class="Comment">//:</span> +<span id="L48" class="LineNr"> 48 </span><span class="Comment">//: integer overflow</span> +<span id="L49" class="LineNr"> 49 </span><span class="Comment">//: division by zero and other undefined expressions</span> +<span id="L50" class="LineNr"> 50 </span><span class="Comment">//: left-shift by negative count</span> +<span id="L51" class="LineNr"> 51 </span><span class="Comment">//: shifting values by more than or equal to the number of bits they contain</span> +<span id="L52" class="LineNr"> 52 </span><span class="Comment">//: bitwise operations on signed numbers</span> +<span id="L53" class="LineNr"> 53 </span><span class="Comment">//:</span> +<span id="L54" class="LineNr"> 54 </span><span class="Comment">//: Converting pointers to types of different alignment requirements</span> +<span id="L55" class="LineNr"> 55 </span><span class="Comment">//: T* -> void* -> T*: defined</span> +<span id="L56" class="LineNr"> 56 </span><span class="Comment">//: T* -> U* -> T*: defined if non-function pointers and alignment requirements are same</span> +<span id="L57" class="LineNr"> 57 </span><span class="Comment">//: function pointers may be cast to other function pointers</span> +<span id="L58" class="LineNr"> 58 </span><span class="Comment">//:</span> +<span id="L59" class="LineNr"> 59 </span><span class="Comment">//: Casting a numeric value into a value that can't be represented by the target type (either directly or via static_cast)</span> +<span id="L60" class="LineNr"> 60 </span><span class="Comment">//:</span> +<span id="L61" class="LineNr"> 61 </span><span class="Comment">//: To guard against these, some conventions:</span> +<span id="L62" class="LineNr"> 62 </span><span class="Comment">//:</span> +<span id="L63" class="LineNr"> 63 </span><span class="Comment">//: 0. Initialize all primitive variables in functions and constructors.</span> +<span id="L64" class="LineNr"> 64 </span><span class="Comment">//:</span> +<span id="L65" class="LineNr"> 65 </span><span class="Comment">//: 1. Minimize use of pointers and pointer arithmetic. Avoid 'new' and</span> +<span id="L66" class="LineNr"> 66 </span><span class="Comment">//: 'delete' as far as possible. Rely on STL to perform memory management to</span> +<span id="L67" class="LineNr"> 67 </span><span class="Comment">//: avoid use-after-free issues (and memory leaks).</span> +<span id="L68" class="LineNr"> 68 </span><span class="Comment">//:</span> +<span id="L69" class="LineNr"> 69 </span><span class="Comment">//: 2. Avoid naked arrays to avoid out-of-bounds access. Never use operator[]</span> +<span id="L70" class="LineNr"> 70 </span><span class="Comment">//: except with map. Use at() with STL vectors and so on.</span> +<span id="L71" class="LineNr"> 71 </span><span class="Comment">//:</span> +<span id="L72" class="LineNr"> 72 </span><span class="Comment">//: 3. Valgrind all the things.</span> +<span id="L73" class="LineNr"> 73 </span><span class="Comment">//:</span> +<span id="L74" class="LineNr"> 74 </span><span class="Comment">//: 4. Avoid unsigned numbers. Not strictly an undefined-behavior issue, but</span> +<span id="L75" class="LineNr"> 75 </span><span class="Comment">//: the extra range doesn't matter, and it's one less confusing category of</span> +<span id="L76" class="LineNr"> 76 </span><span class="Comment">//: interaction gotchas to worry about.</span> +<span id="L77" class="LineNr"> 77 </span><span class="Comment">//:</span> +<span id="L78" class="LineNr"> 78 </span><span class="Comment">//: Corollary: don't use the size() method on containers, since it returns an</span> +<span id="L79" class="LineNr"> 79 </span><span class="Comment">//: unsigned and that'll cause warnings about mixing signed and unsigned,</span> +<span id="L80" class="LineNr"> 80 </span><span class="Comment">//: yadda-yadda. Instead use this macro below to perform an unsafe cast to</span> +<span id="L81" class="LineNr"> 81 </span><span class="Comment">//: signed. We'll just give up immediately if a container's ever too large.</span> +<span id="L82" class="LineNr"> 82 </span><span class="Comment">//: Basically, Mu is not concerned about this being a little slower than it</span> +<span id="L83" class="LineNr"> 83 </span><span class="Comment">//: could be. (<a href="https://gist.github.com/rygorous/e0f055bfb74e3d5f0af20690759de5a7)">https://gist.github.com/rygorous/e0f055bfb74e3d5f0af20690759de5a7)</a></span> +<span id="L84" class="LineNr"> 84 </span><span class="Comment">//:</span> +<span id="L85" class="LineNr"> 85 </span><span class="Comment">//: Addendum to corollary: We're going to uniformly use int everywhere, to</span> +<span id="L86" class="LineNr"> 86 </span><span class="Comment">//: indicate that we're oblivious to number size, and since Clang on 32-bit</span> +<span id="L87" class="LineNr"> 87 </span><span class="Comment">//: platforms doesn't yet support multiplication over 64-bit integers, and</span> +<span id="L88" class="LineNr"> 88 </span><span class="Comment">//: since multiplying two integers seems like a more common situation to end</span> +<span id="L89" class="LineNr"> 89 </span><span class="Comment">//: up in than integer overflow.</span> +<span id="L90" class="LineNr"> 90 </span><span class="Delimiter">:(before "End Includes")</span> +<span id="L91" class="LineNr"> 91 </span><span class="PreProc">#define SIZE(X) (assert((X)</span><span class="Delimiter">.</span><span class="PreProc">size() < (</span><span class="Constant">1LL</span><span class="PreProc"><<(</span><span class="Normal">sizeof</span><span class="PreProc">(</span><span class="Normal">int</span><span class="PreProc">)*</span><span class="Constant">8</span><span class="PreProc">-</span><span class="Constant">2</span><span class="PreProc">)))</span><span class="Delimiter">,</span><span class="PreProc"> </span><span class="Normal">static_cast</span><span class="PreProc"><</span><span class="Normal">int</span><span class="PreProc">>((X)</span><span class="Delimiter">.</span><span class="PreProc">size()))</span> +<span id="L92" class="LineNr"> 92 </span> +<span id="L93" class="LineNr"> 93 </span><span class="Comment">//: 5. Integer overflow is guarded against at runtime using the -ftrapv flag</span> +<span id="L94" class="LineNr"> 94 </span><span class="Comment">//: to the compiler, supported by Clang (GCC version only works sometimes:</span> +<span id="L95" class="LineNr"> 95 </span><span class="Comment">//: <a href="http://stackoverflow.com/questions/20851061/how-to-make-gcc-ftrapv-work).">http://stackoverflow.com/questions/20851061/how-to-make-gcc-ftrapv-work).</a></span> +<span id="L96" class="LineNr"> 96 </span><span class="Delimiter">:(before "atexit(reset)")</span> +<span id="L97" class="LineNr"> 97 </span>initialize_signal_handlers<span class="Delimiter">();</span> <span class="Comment">// not always necessary, but doesn't hurt</span> +<span id="L98" class="LineNr"> 98 </span><span class="CommentedCode">//? cerr << INT_MAX+1 << '\n'; // test overflow</span> +<span id="L99" class="LineNr"> 99 </span><span class="CommentedCode">//? assert(false); // test SIGABRT</span> +<span id="L100" class="LineNr">100 </span><span class="Delimiter">:(code)</span> +<span id="L101" class="LineNr">101 </span><span class="Comment">// based on <a href="https://spin.atomicobject.com/2013/01/13/exceptions-stack-traces-c">https://spin.atomicobject.com/2013/01/13/exceptions-stack-traces-c</a></span> +<span id="L102" class="LineNr">102 </span><span class="Normal">void</span> initialize_signal_handlers<span class="Delimiter">()</span> <span class="Delimiter">{</span> +<span id="L103" class="LineNr">103 </span> <span class="Normal">struct</span> sigaction action<span class="Delimiter">;</span> +<span id="L104" class="LineNr">104 </span> bzero<span class="Delimiter">(</span>&action<span class="Delimiter">,</span> <span class="Normal">sizeof</span><span class="Delimiter">(</span>action<span class="Delimiter">));</span> +<span id="L105" class="LineNr">105 </span> action<span class="Delimiter">.</span>sa_sigaction = dump_and_exit<span class="Delimiter">;</span> +<span id="L106" class="LineNr">106 </span> sigemptyset<span class="Delimiter">(</span>&action<span class="Delimiter">.</span>sa_mask<span class="Delimiter">);</span> +<span id="L107" class="LineNr">107 </span> sigaction<span class="Delimiter">(</span><span class="Constant">SIGABRT</span><span class="Delimiter">,</span> &action<span class="Delimiter">,</span> <span class="Constant">NULL</span><span class="Delimiter">);</span> <span class="Comment">// assert() failure or integer overflow on linux (with -ftrapv)</span> +<span id="L108" class="LineNr">108 </span> sigaction<span class="Delimiter">(</span><span class="Constant">SIGILL</span><span class="Delimiter">,</span> &action<span class="Delimiter">,</span> <span class="Constant">NULL</span><span class="Delimiter">);</span> <span class="Comment">// integer overflow on OS X (with -ftrapv)</span> +<span id="L109" class="LineNr">109 </span><span class="Delimiter">}</span> +<span id="L110" class="LineNr">110 </span><span class="Normal">void</span> dump_and_exit<span class="Delimiter">(</span><span class="Normal">int</span> sig<span class="Delimiter">,</span> unused siginfo_t* dummy1<span class="Delimiter">,</span> unused <span class="Normal">void</span>* dummy2<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L111" class="LineNr">111 </span> <span class="Normal">switch</span> <span class="Delimiter">(</span>sig<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L112" class="LineNr">112 </span> <span class="Conceal">¦</span> <span class="Normal">case</span> <span class="Constant">SIGABRT</span>: +<span id="L113" class="LineNr">113 </span><span class="PreProc"> </span><span class="Conceal">¦</span><span class="PreProc"> </span><span class="Conceal">¦</span><span class="PreProc"> #ifndef __APPLE__</span> +<span id="L114" class="LineNr">114 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> cerr << <span class="Constant">"SIGABRT: might be an integer overflow if it wasn't an assert() failure</span><span class="cSpecial">\n</span><span class="Constant">"</span><span class="Delimiter">;</span> +<span id="L115" class="LineNr">115 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> _Exit<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">);</span> +<span id="L116" class="LineNr">116 </span><span class="PreProc"> </span><span class="Conceal">¦</span><span class="PreProc"> </span><span class="Conceal">¦</span><span class="PreProc"> #endif</span> +<span id="L117" class="LineNr">117 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Identifier">break</span><span class="Delimiter">;</span> +<span id="L118" class="LineNr">118 </span> <span class="Conceal">¦</span> <span class="Normal">case</span> <span class="Constant">SIGILL</span>: +<span id="L119" class="LineNr">119 </span><span class="PreProc"> </span><span class="Conceal">¦</span><span class="PreProc"> </span><span class="Conceal">¦</span><span class="PreProc"> #ifdef __APPLE__</span> +<span id="L120" class="LineNr">120 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> cerr << <span class="Constant">"SIGILL: most likely caused by integer overflow</span><span class="cSpecial">\n</span><span class="Constant">"</span><span class="Delimiter">;</span> +<span id="L121" class="LineNr">121 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> _Exit<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">);</span> +<span id="L122" class="LineNr">122 </span><span class="PreProc"> </span><span class="Conceal">¦</span><span class="PreProc"> </span><span class="Conceal">¦</span><span class="PreProc"> #endif</span> +<span id="L123" class="LineNr">123 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Identifier">break</span><span class="Delimiter">;</span> +<span id="L124" class="LineNr">124 </span> <span class="Conceal">¦</span> <span class="Normal">default</span>: +<span id="L125" class="LineNr">125 </span> <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Identifier">break</span><span class="Delimiter">;</span> +<span id="L126" class="LineNr">126 </span> <span class="Delimiter">}</span> +<span id="L127" class="LineNr">127 </span><span class="Delimiter">}</span> +<span id="L128" class="LineNr">128 </span><span class="Delimiter">:(before "End Includes")</span> +<span id="L129" class="LineNr">129 </span><span class="PreProc">#include </span><span class="Constant"><signal.h></span> +<span id="L130" class="LineNr">130 </span> +<span id="L131" class="LineNr">131 </span><span class="Comment">//: For good measure we'll also enable SIGFPE.</span> +<span id="L132" class="LineNr">132 </span><span class="Delimiter">:(before "atexit(reset)")</span> +<span id="L133" class="LineNr">133 </span>feenableexcept<span class="Delimiter">(</span>FE_OVERFLOW | FE_UNDERFLOW<span class="Delimiter">);</span> +<span id="L134" class="LineNr">134 </span><span class="CommentedCode">//? assert(sizeof(int) == 4 && sizeof(float) == 4);</span> +<span id="L135" class="LineNr">135 </span><span class="CommentedCode">//? // | exp | mantissa</span> +<span id="L136" class="LineNr">136 </span><span class="CommentedCode">//? int smallest_subnormal = 0b00000000000000000000000000000001;</span> +<span id="L137" class="LineNr">137 </span><span class="CommentedCode">//? float smallest_subnormal_f = *reinterpret_cast<float*>(&smallest_subnormal);</span> +<span id="L138" class="LineNr">138 </span><span class="CommentedCode">//? cerr << "ε: " << smallest_subnormal_f << '\n';</span> +<span id="L139" class="LineNr">139 </span><span class="CommentedCode">//? cerr << "ε/2: " << smallest_subnormal_f/2 << " (underflow)\n"; // test SIGFPE</span> +<span id="L140" class="LineNr">140 </span><span class="Delimiter">:(before "End Includes")</span> +<span id="L141" class="LineNr">141 </span><span class="PreProc">#include </span><span class="Constant"><fenv.h></span> +<span id="L142" class="LineNr">142 </span><span class="Delimiter">:(code)</span> +<span id="L143" class="LineNr">143 </span><span class="PreProc">#ifdef __APPLE__</span> +<span id="L144" class="LineNr">144 </span><span class="Comment">// Public domain polyfill for feenableexcept on OS X</span> +<span id="L145" class="LineNr">145 </span><span class="Comment">// <a href="http://www-personal.umich.edu/~williams/archive/computation/fe-handling-example.c">http://www-personal.umich.edu/~williams/archive/computation/fe-handling-example.c</a></span> +<span id="L146" class="LineNr">146 </span><span class="Normal">int</span> feenableexcept <span class="Delimiter">(</span><span class="Normal">unsigned</span> <span class="Normal">int</span> excepts<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L147" class="LineNr">147 </span> <span class="Normal">static</span> fenv_t fenv<span class="Delimiter">;</span> +<span id="L148" class="LineNr">148 </span> <span class="Normal">unsigned</span> <span class="Normal">int</span> new_excepts = excepts & FE_ALL_EXCEPT<span class="Delimiter">;</span> +<span id="L149" class="LineNr">149 </span> <span class="Normal">unsigned</span> <span class="Normal">int</span> old_excepts<span class="Delimiter">;</span> +<span id="L150" class="LineNr">150 </span> <span class="Normal">if</span> <span class="Delimiter">(</span>fegetenv<span class="Delimiter">(</span>&fenv<span class="Delimiter">))</span> <span class="Identifier">return</span> -<span class="Constant">1</span><span class="Delimiter">;</span> +<span id="L151" class="LineNr">151 </span> old_excepts = fenv<span class="Delimiter">.</span>__control & FE_ALL_EXCEPT<span class="Delimiter">;</span> +<span id="L152" class="LineNr">152 </span> fenv<span class="Delimiter">.</span>__control &= ~new_excepts<span class="Delimiter">;</span> +<span id="L153" class="LineNr">153 </span> fenv<span class="Delimiter">.</span>__mxcsr &= ~<span class="Delimiter">(</span>new_excepts << <span class="Constant">7</span><span class="Delimiter">);</span> +<span id="L154" class="LineNr">154 </span> <span class="Identifier">return</span> fesetenv<span class="Delimiter">(</span>&fenv<span class="Delimiter">)</span> ? -<span class="Constant">1</span> : old_excepts<span class="Delimiter">;</span> +<span id="L155" class="LineNr">155 </span><span class="Delimiter">}</span> +<span id="L156" class="LineNr">156 </span><span class="PreProc">#endif</span> +<span id="L157" class="LineNr">157 </span> +<span id="L158" class="LineNr">158 </span><span class="Comment">//: 6. Map's operator[] being non-const is fucking evil.</span> +<span id="L159" class="LineNr">159 </span><span class="Delimiter">:(before "Globals")</span> <span class="Comment">// can't generate prototypes for these</span> +<span id="L160" class="LineNr">160 </span><span class="Comment">// from <a href="http://stackoverflow.com/questions/152643/idiomatic-c-for-reading-from-a-const-map">http://stackoverflow.com/questions/152643/idiomatic-c-for-reading-from-a-const-map</a></span> +<span id="L161" class="LineNr">161 </span><span class="Normal">template</span><<span class="Normal">typename</span> T> <span class="Normal">typename</span> T::mapped_type& get<span class="Delimiter">(</span>T& map<span class="Delimiter">,</span> <span class="Normal">typename</span> T::key_type <span class="Normal">const</span>& key<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L162" class="LineNr">162 </span> <span class="Normal">typename</span> T::iterator iter<span class="Delimiter">(</span>map<span class="Delimiter">.</span>find<span class="Delimiter">(</span>key<span class="Delimiter">));</span> +<span id="L163" class="LineNr">163 </span> assert<span class="Delimiter">(</span>iter != map<span class="Delimiter">.</span>end<span class="Delimiter">());</span> +<span id="L164" class="LineNr">164 </span> <span class="Identifier">return</span> iter<span class="Delimiter">-></span>second<span class="Delimiter">;</span> +<span id="L165" class="LineNr">165 </span><span class="Delimiter">}</span> +<span id="L166" class="LineNr">166 </span><span class="Normal">template</span><<span class="Normal">typename</span> T> <span class="Normal">typename</span> T::mapped_type <span class="Normal">const</span>& get<span class="Delimiter">(</span><span class="Normal">const</span> T& map<span class="Delimiter">,</span> <span class="Normal">typename</span> T::key_type <span class="Normal">const</span>& key<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L167" class="LineNr">167 </span> <span class="Normal">typename</span> T::const_iterator iter<span class="Delimiter">(</span>map<span class="Delimiter">.</span>find<span class="Delimiter">(</span>key<span class="Delimiter">));</span> +<span id="L168" class="LineNr">168 </span> assert<span class="Delimiter">(</span>iter != map<span class="Delimiter">.</span>end<span class="Delimiter">());</span> +<span id="L169" class="LineNr">169 </span> <span class="Identifier">return</span> iter<span class="Delimiter">-></span>second<span class="Delimiter">;</span> +<span id="L170" class="LineNr">170 </span><span class="Delimiter">}</span> +<span id="L171" class="LineNr">171 </span><span class="Normal">template</span><<span class="Normal">typename</span> T> <span class="Normal">typename</span> T::mapped_type <span class="Normal">const</span>& put<span class="Delimiter">(</span>T& map<span class="Delimiter">,</span> <span class="Normal">typename</span> T::key_type <span class="Normal">const</span>& key<span class="Delimiter">,</span> <span class="Normal">typename</span> T::mapped_type <span class="Normal">const</span>& value<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L172" class="LineNr">172 </span> map[key] = value<span class="Delimiter">;</span> +<span id="L173" class="LineNr">173 </span> <span class="Identifier">return</span> map[key]<span class="Delimiter">;</span> +<span id="L174" class="LineNr">174 </span><span class="Delimiter">}</span> +<span id="L175" class="LineNr">175 </span><span class="Normal">template</span><<span class="Normal">typename</span> T> <span class="Normal">bool</span> contains_key<span class="Delimiter">(</span>T& map<span class="Delimiter">,</span> <span class="Normal">typename</span> T::key_type <span class="Normal">const</span>& key<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L176" class="LineNr">176 </span> <span class="Identifier">return</span> map<span class="Delimiter">.</span>find<span class="Delimiter">(</span>key<span class="Delimiter">)</span> != map<span class="Delimiter">.</span>end<span class="Delimiter">();</span> +<span id="L177" class="LineNr">177 </span><span class="Delimiter">}</span> +<span id="L178" class="LineNr">178 </span><span class="Normal">template</span><<span class="Normal">typename</span> T> <span class="Normal">typename</span> T::mapped_type& get_or_insert<span class="Delimiter">(</span>T& map<span class="Delimiter">,</span> <span class="Normal">typename</span> T::key_type <span class="Normal">const</span>& key<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L179" class="LineNr">179 </span> <span class="Identifier">return</span> map[key]<span class="Delimiter">;</span> +<span id="L180" class="LineNr">180 </span><span class="Delimiter">}</span> +<span id="L181" class="LineNr">181 </span><span class="Comment">//: The contract: any container that relies on get_or_insert should never call</span> +<span id="L182" class="LineNr">182 </span><span class="Comment">//: contains_key.</span> +<span id="L183" class="LineNr">183 </span> +<span id="L184" class="LineNr">184 </span><span class="Comment">//: 7. istreams are a royal pain in the arse. You have to be careful about</span> +<span id="L185" class="LineNr">185 </span><span class="Comment">//: what subclass you try to putback into. You have to watch out for the pesky</span> +<span id="L186" class="LineNr">186 </span><span class="Comment">//: failbit and badbit. Just avoid eof() and use this helper instead.</span> +<span id="L187" class="LineNr">187 </span><span class="Delimiter">:(code)</span> +<span id="L188" class="LineNr">188 </span><span class="Normal">bool</span> has_data<span class="Delimiter">(</span>istream& in<span class="Delimiter">)</span> <span class="Delimiter">{</span> +<span id="L189" class="LineNr">189 </span> <span class="Identifier">return</span> in && !in<span class="Delimiter">.</span>eof<span class="Delimiter">();</span> +<span id="L190" class="LineNr">190 </span><span class="Delimiter">}</span> +<span id="L191" class="LineNr">191 </span> +<span id="L192" class="LineNr">192 </span><span class="Delimiter">:(before "End Includes")</span> +<span id="L193" class="LineNr">193 </span><span class="PreProc">#include </span><span class="Constant"><assert.h></span> +<span id="L194" class="LineNr">194 </span> +<span id="L195" class="LineNr">195 </span><span class="PreProc">#include </span><span class="Constant"><iostream></span> +<span id="L196" class="LineNr">196 </span><span class="Normal">using</span> std::istream<span class="Delimiter">;</span> +<span id="L197" class="LineNr">197 </span><span class="Normal">using</span> std::ostream<span class="Delimiter">;</span> +<span id="L198" class="LineNr">198 </span><span class="Normal">using</span> std::iostream<span class="Delimiter">;</span> +<span id="L199" class="LineNr">199 </span><span class="Normal">using</span> std::cin<span class="Delimiter">;</span> +<span id="L200" class="LineNr">200 </span><span class="Normal">using</span> std::cout<span class="Delimiter">;</span> +<span id="L201" class="LineNr">201 </span><span class="Normal">using</span> std::cerr<span class="Delimiter">;</span> +<span id="L202" class="LineNr">202 </span><span class="PreProc">#include </span><span class="Constant"><iomanip></span> +<span id="L203" class="LineNr">203 </span> +<span id="L204" class="LineNr">204 </span><span class="PreProc">#include </span><span class="Constant"><string.h></span> +<span id="L205" class="LineNr">205 </span><span class="PreProc">#include </span><span class="Constant"><string></span> +<span id="L206" class="LineNr">206 </span><span class="Normal">using</span> std::string<span class="Delimiter">;</span> +<span id="L207" class="LineNr">207 </span> +<span id="L208" class="LineNr">208 </span><span class="PreProc">#define unused __attribute__((unused))</span> +</pre> +</body> +</html> +<!-- vim: set foldmethod=manual : --> |