{"id":2076,"date":"2025-01-27T20:12:52","date_gmt":"2025-01-27T20:12:52","guid":{"rendered":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/?page_id=2076"},"modified":"2025-01-27T21:25:26","modified_gmt":"2025-01-27T21:25:26","slug":"template-value-parameter-usage","status":"publish","type":"page","link":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/topics\/c-details\/function-templates-2\/template-value-parameter-usage\/","title":{"rendered":"Template Value Parameter Usage"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Template_Value_Parameter_Usage\"><\/span>Template Value Parameter Usage<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>There are restrictions on the types available for use in template value parameters. A non-type parameter can be any of the following types:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>An integral type<\/li>\n\n\n\n<li>An enumeration type<\/li>\n\n\n\n<li>A pointer or reference to a class object<\/li>\n\n\n\n<li>A pointer or reference to a function<\/li>\n\n\n\n<li>A pointer or reference to a class member function<\/li>\n\n\n\n<li>std::nullptr_t<\/li>\n\n\n\n<li>A floating point type (since C++20)<\/li>\n<\/ul>\n\n\n\n<p>Here are some examples of where value parameters can be used:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Compile-time_Operations\"><\/span>Compile-time Operations<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-kevinbatdorf-code-block-pro cbp-has-line-numbers\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono-NL.ttf\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono-NL,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;--cbp-line-number-color:#000000;--cbp-line-number-width:calc(2 * 0.6 * .875rem);line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span role=\"button\" tabindex=\"0\" data-code=\"\/\/\n\/\/  main.cpp\n\/\/  Factorial Template\n\/\/\n\/\/  Created by Bryan Higgs on 10\/15\/24.\n\/\/\n\n#include &lt;iostream&gt;\n\ntemplate &lt;int N&gt;\nconstexpr int factorial()\n{\n  int value = 1; \/\/ 0! = 1\n  for (int i = 1; i &lt;= N; i++)\n  {\n    value *= i;\n  }\n  return value;\n}\n\nint main(int argc, const char * argv[])\n{\n  std::cout &lt;&lt; &quot;5 factorial = &quot;\n            &lt;&lt; factorial&lt;5&gt;() &lt;&lt; std::endl;\n  std::cout &lt;&lt; &quot;10 factorial = &quot;\n            &lt;&lt; factorial&lt;10&gt;() &lt;&lt; std::endl;\n  \n  return 0;\n}\" style=\"color:#000000;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki light-plus\" style=\"background-color: #FFFFFF\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #008000\">\/\/<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/  main.cpp<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/  Factorial Template<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/  Created by Bryan Higgs on 10\/15\/24.<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #AF00DB\">#include<\/span><span style=\"color: #0000FF\"> <\/span><span style=\"color: #A31515\">&lt;iostream&gt;<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">template<\/span><span style=\"color: #000000\"> &lt;<\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #267F99\">N<\/span><span style=\"color: #000000\">&gt;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">constexpr<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #795E26\">factorial<\/span><span style=\"color: #000000\">()<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> value = <\/span><span style=\"color: #098658\">1<\/span><span style=\"color: #000000\">;<\/span><span style=\"color: #008000\"> \/\/ 0! = 1<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">for<\/span><span style=\"color: #000000\"> (<\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> i = <\/span><span style=\"color: #098658\">1<\/span><span style=\"color: #000000\">; i &lt;= N; i++)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  {<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">    value *= i;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  }<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">return<\/span><span style=\"color: #000000\"> value;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">}<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #795E26\">main<\/span><span style=\"color: #000000\">(<\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">argc<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #0000FF\">const<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #0000FF\">char<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #0000FF\">*<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">argv<\/span><span style=\"color: #000000\">[])<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::cout &lt;&lt; <\/span><span style=\"color: #A31515\">&quot;5 factorial = &quot;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">            &lt;&lt; <\/span><span style=\"color: #795E26\">factorial<\/span><span style=\"color: #000000\">&lt;<\/span><span style=\"color: #098658\">5<\/span><span style=\"color: #000000\">&gt;() &lt;&lt; <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::endl;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::cout &lt;&lt; <\/span><span style=\"color: #A31515\">&quot;10 factorial = &quot;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">            &lt;&lt; <\/span><span style=\"color: #795E26\">factorial<\/span><span style=\"color: #000000\">&lt;<\/span><span style=\"color: #098658\">10<\/span><span style=\"color: #000000\">&gt;() &lt;&lt; <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::endl;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">return<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #098658\">0<\/span><span style=\"color: #000000\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">}<\/span><\/span><\/code><\/pre><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>This program produces the following output:<\/p>\n\n\n\n<pre class=\"wp-block-code\" style=\"padding-top:0px;padding-bottom:0px\"><code><strong>5 factorial = 120\n10 factorial = 3628800\nProgram ended with exit code: 0<\/strong><\/code><\/pre>\n\n\n\n<p>You can implement a recursive solution, too:<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro cbp-has-line-numbers\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono-NL.ttf\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono-NL,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;--cbp-line-number-color:#000000;--cbp-line-number-width:calc(2 * 0.6 * .875rem);--cbp-line-highlight-color:rgba(0, 0, 0, 0.2);line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span role=\"button\" tabindex=\"0\" data-code=\"\/\/\n\/\/  main.cpp\n\/\/  Factorial Template\n\/\/\n\/\/  Created by Bryan Higgs on 10\/15\/24.\n\/\/\n\n#include &lt;iostream&gt;\n\ntemplate &lt;int N&gt;\nconstexpr int factorial()\n{\n  \/\/ A compile-time if which drops the non-hitting block immediately\n  if constexpr (N == 0) return 1;\n  else return N * factorial&lt;N - 1&gt;();\n}\n\nint main(int argc, const char * argv[])\n{\n  std::cout &lt;&lt; &quot;5 factorial = &quot;\n            &lt;&lt; factorial&lt;5&gt;() &lt;&lt; std::endl;\n  std::cout &lt;&lt; &quot;10 factorial = &quot;\n            &lt;&lt; factorial&lt;10&gt;() &lt;&lt; std::endl;\n  \n  return 0;\n}\" style=\"color:#000000;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki light-plus\" style=\"background-color: #FFFFFF\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #008000\">\/\/<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/  main.cpp<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/  Factorial Template<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/  Created by Bryan Higgs on 10\/15\/24.<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #AF00DB\">#include<\/span><span style=\"color: #0000FF\"> <\/span><span style=\"color: #A31515\">&lt;iostream&gt;<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">template<\/span><span style=\"color: #000000\"> &lt;<\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #267F99\">N<\/span><span style=\"color: #000000\">&gt;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">constexpr<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #795E26\">factorial<\/span><span style=\"color: #000000\">()<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">  \/\/ A compile-time if which drops the non-hitting block immediately<\/span><\/span>\n<span class=\"line cbp-line-highlight\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">if<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #0000FF\">constexpr<\/span><span style=\"color: #000000\"> (N == <\/span><span style=\"color: #098658\">0<\/span><span style=\"color: #000000\">) <\/span><span style=\"color: #AF00DB\">return<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #098658\">1<\/span><span style=\"color: #000000\">;<\/span><\/span>\n<span class=\"line cbp-line-highlight\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">else<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #AF00DB\">return<\/span><span style=\"color: #000000\"> N * <\/span><span style=\"color: #795E26\">factorial<\/span><span style=\"color: #000000\">&lt;<\/span><span style=\"color: #267F99\">N<\/span><span style=\"color: #000000\"> - <\/span><span style=\"color: #098658\">1<\/span><span style=\"color: #000000\">&gt;();<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">}<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #795E26\">main<\/span><span style=\"color: #000000\">(<\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">argc<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #0000FF\">const<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #0000FF\">char<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #0000FF\">*<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">argv<\/span><span style=\"color: #000000\">[])<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::cout &lt;&lt; <\/span><span style=\"color: #A31515\">&quot;5 factorial = &quot;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">            &lt;&lt; <\/span><span style=\"color: #795E26\">factorial<\/span><span style=\"color: #000000\">&lt;<\/span><span style=\"color: #098658\">5<\/span><span style=\"color: #000000\">&gt;() &lt;&lt; <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::endl;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::cout &lt;&lt; <\/span><span style=\"color: #A31515\">&quot;10 factorial = &quot;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">            &lt;&lt; <\/span><span style=\"color: #795E26\">factorial<\/span><span style=\"color: #000000\">&lt;<\/span><span style=\"color: #098658\">10<\/span><span style=\"color: #000000\">&gt;() &lt;&lt; <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::endl;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">return<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #098658\">0<\/span><span style=\"color: #000000\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>Note that, in this case, the keyword <strong>constexpr<\/strong> is required, to ensure that the if statement is a compile-time construct. Without the <strong>constexpr<\/strong>, you get very confusing and peculiar results.<\/p>\n<\/blockquote>\n<\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Allocating_a_Fixed-size_Buffer\"><\/span>Allocating a Fixed-size Buffer<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-kevinbatdorf-code-block-pro cbp-has-line-numbers\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono-NL.ttf\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono-NL,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;--cbp-line-number-color:#000000;--cbp-line-number-width:calc(2 * 0.6 * .875rem);line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span role=\"button\" tabindex=\"0\" data-code=\"\/\/\n\/\/  main.cpp\n\/\/  Fixed-size Array Template\n\/\/\n\/\/  Created by Bryan Higgs on 10\/15\/24.\n\/\/\n\n#include &lt;iostream&gt;\n\ntemplate &lt;typename T, size_t size&gt;\nT* Buffer ( const T* initValues )\n{\n  T* alloc = new T[size];\n  for (int i = 0; i &lt; size; i++ )\n  {\n    alloc[i] = initValues[i];\n  }\n  return alloc;\n}\n\ntemplate &lt;typename T&gt;\nvoid printBuffer(const T* buf, size_t size)\n{\n  std::cout &lt;&lt; &quot;Buffer: \\n&quot;;\n  for (int i = 0; i &lt; size; i++)\n  {\n    std::cout &lt;&lt; &quot; [&quot; &lt;&lt; i &lt;&lt; &quot;] &quot; &lt;&lt; buf[i]\n              &lt;&lt; std::endl;\n  }\n}\n\nint main(int argc, const char * argv[])\n{\n  int initIntValues[] { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 };\n  int* intArray = Buffer&lt;int, 10&gt;( initIntValues );\n  printBuffer( intArray , 10);\n  \n  double initDoubleValues[] { 27.3, 1.4, 5.2, 11.9, 71.2};\n  double* doubleArray = Buffer&lt;double, 5&gt;( initDoubleValues );\n  printBuffer( doubleArray, 5);\n  \n  \/\/ Tidy up\n  delete [] intArray;\n  delete [] doubleArray;\n\n  return 0;\n}\" style=\"color:#000000;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki light-plus\" style=\"background-color: #FFFFFF\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #008000\">\/\/<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/  main.cpp<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/  Fixed-size Array Template<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/  Created by Bryan Higgs on 10\/15\/24.<\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">\/\/<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #AF00DB\">#include<\/span><span style=\"color: #0000FF\"> <\/span><span style=\"color: #A31515\">&lt;iostream&gt;<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">template<\/span><span style=\"color: #000000\"> &lt;<\/span><span style=\"color: #0000FF\">typename<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #267F99\">T<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #0000FF\">size_t<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #267F99\">size<\/span><span style=\"color: #000000\">&gt;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #267F99\">T<\/span><span style=\"color: #0000FF\">*<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #795E26\">Buffer<\/span><span style=\"color: #000000\"> ( <\/span><span style=\"color: #0000FF\">const<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #267F99\">T<\/span><span style=\"color: #0000FF\">*<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">initValues<\/span><span style=\"color: #000000\"> )<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  T* alloc = <\/span><span style=\"color: #AF00DB\">new<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">T<\/span><span style=\"color: #000000\">[size];<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">for<\/span><span style=\"color: #000000\"> (<\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> i = <\/span><span style=\"color: #098658\">0<\/span><span style=\"color: #000000\">; i &lt; size; i++ )<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  {<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">    <\/span><span style=\"color: #001080\">alloc<\/span><span style=\"color: #000000\">[i] = <\/span><span style=\"color: #001080\">initValues<\/span><span style=\"color: #000000\">[i];<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  }<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">return<\/span><span style=\"color: #000000\"> alloc;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">}<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">template<\/span><span style=\"color: #000000\"> &lt;<\/span><span style=\"color: #0000FF\">typename<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #267F99\">T<\/span><span style=\"color: #000000\">&gt;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">void<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #795E26\">printBuffer<\/span><span style=\"color: #000000\">(<\/span><span style=\"color: #0000FF\">const<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #267F99\">T<\/span><span style=\"color: #0000FF\">*<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">buf<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #0000FF\">size_t<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">size<\/span><span style=\"color: #000000\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::cout &lt;&lt; <\/span><span style=\"color: #A31515\">&quot;Buffer: <\/span><span style=\"color: #EE0000\">\\n<\/span><span style=\"color: #A31515\">&quot;<\/span><span style=\"color: #000000\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">for<\/span><span style=\"color: #000000\"> (<\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> i = <\/span><span style=\"color: #098658\">0<\/span><span style=\"color: #000000\">; i &lt; size; i++)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  {<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">    <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::cout &lt;&lt; <\/span><span style=\"color: #A31515\">&quot; [&quot;<\/span><span style=\"color: #000000\"> &lt;&lt; i &lt;&lt; <\/span><span style=\"color: #A31515\">&quot;] &quot;<\/span><span style=\"color: #000000\"> &lt;&lt; <\/span><span style=\"color: #001080\">buf<\/span><span style=\"color: #000000\">[i]<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">              &lt;&lt; <\/span><span style=\"color: #267F99\">std<\/span><span style=\"color: #000000\">::endl;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  }<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">}<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #795E26\">main<\/span><span style=\"color: #000000\">(<\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">argc<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #0000FF\">const<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #0000FF\">char<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #0000FF\">*<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #001080\">argv<\/span><span style=\"color: #000000\">[])<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">{<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\"> initIntValues[] { <\/span><span style=\"color: #098658\">2<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">4<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">6<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">8<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">10<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">12<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">14<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">16<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">18<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">20<\/span><span style=\"color: #000000\"> };<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\">* intArray = <\/span><span style=\"color: #795E26\">Buffer<\/span><span style=\"color: #000000\">&lt;<\/span><span style=\"color: #0000FF\">int<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">10<\/span><span style=\"color: #000000\">&gt;( initIntValues );<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #795E26\">printBuffer<\/span><span style=\"color: #000000\">( intArray , <\/span><span style=\"color: #098658\">10<\/span><span style=\"color: #000000\">);<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #0000FF\">double<\/span><span style=\"color: #000000\"> initDoubleValues[] { <\/span><span style=\"color: #098658\">27.3<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">1.4<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">5.2<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">11.9<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">71.2<\/span><span style=\"color: #000000\">};<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #0000FF\">double<\/span><span style=\"color: #000000\">* doubleArray = <\/span><span style=\"color: #795E26\">Buffer<\/span><span style=\"color: #000000\">&lt;<\/span><span style=\"color: #0000FF\">double<\/span><span style=\"color: #000000\">, <\/span><span style=\"color: #098658\">5<\/span><span style=\"color: #000000\">&gt;( initDoubleValues );<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #795E26\">printBuffer<\/span><span style=\"color: #000000\">( doubleArray, <\/span><span style=\"color: #098658\">5<\/span><span style=\"color: #000000\">);<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><\/span>\n<span class=\"line\"><span style=\"color: #008000\">  \/\/ Tidy up<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">delete<\/span><span style=\"color: #0000FF\"> <\/span><span style=\"color: #AF00DB\">[]<\/span><span style=\"color: #000000\"> intArray;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">delete<\/span><span style=\"color: #0000FF\"> <\/span><span style=\"color: #AF00DB\">[]<\/span><span style=\"color: #000000\"> doubleArray;<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #000000\">  <\/span><span style=\"color: #AF00DB\">return<\/span><span style=\"color: #000000\"> <\/span><span style=\"color: #098658\">0<\/span><span style=\"color: #000000\">;<\/span><\/span>\n<span class=\"line\"><span style=\"color: #000000\">}<\/span><\/span><\/code><\/pre><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>This program produces the following output:<\/p>\n\n\n\n<pre class=\"wp-block-code\" style=\"padding-top:0px;padding-bottom:0px\"><code><strong>Buffer: \n &#91;0] 2\n &#91;1] 4\n &#91;2] 6\n &#91;3] 8\n &#91;4] 10\n &#91;5] 12\n &#91;6] 14\n &#91;7] 16\n &#91;8] 18\n &#91;9] 20\nBuffer: \n &#91;0] 27.3\n &#91;1] 1.4\n &#91;2] 5.2\n &#91;3] 11.9\n &#91;4] 71.2\nProgram ended with exit code: 0<\/strong><\/code><\/pre>\n<\/div>\n<\/div>\n\n\n\n<p>There are other uses for template value parameters, but many are rather esoteric and beyond the scope of this tutorial.<\/p>\n\n\n\n<div style=\"height:47px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-font-size has-medium-font-size\"><a class=\"wp-block-button__link has-palette-color-8-color has-text-color has-link-color wp-element-button\" href=\"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/topics\/c-details\/function-templates-2\/summary-of-function-templates\/\">Next: Summary of Function Templates<\/a><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Template Value Parameter Usage There are restrictions on the types available for use in template value parameters. A non-type parameter can be any of the following types: Here are some examples of where value parameters can be used: Compile-time Operations This program produces the following output: You can implement a recursive solution, too: Note that, [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2029,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-2076","page","type-page","status-publish","hentry"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/wp-json\/wp\/v2\/pages\/2076","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/wp-json\/wp\/v2\/comments?post=2076"}],"version-history":[{"count":3,"href":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/wp-json\/wp\/v2\/pages\/2076\/revisions"}],"predecessor-version":[{"id":2101,"href":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/wp-json\/wp\/v2\/pages\/2076\/revisions\/2101"}],"up":[{"embeddable":true,"href":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/wp-json\/wp\/v2\/pages\/2029"}],"wp:attachment":[{"href":"https:\/\/bhiggs.x10hosting.com\/PracticalCPlusPlusProgramming\/index.php\/wp-json\/wp\/v2\/media?parent=2076"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}