Peter M. Groen / CLI11

Commit b73d1bd9b23abaa4d01f76578627c7f5cf83aaf9

Authored by Henry Fredrick Schreiner
1 parent aae31265

Trying enable if, new version

Inline Side-by-side
Showing 1 changed file with 24 additions and 18 deletions
include/CLI.hpp
  View file @b73d1bd
... ... @@ -36,6 +36,18 @@ std::string join(const T& v, std::string delim = ",") {
36 36  
37 37 namespace CLI {
38 38  
  39 +// Based generally on https://rmf.io/cxx11/almost-static-if
  40 +namespace detail {
  41 + enum class enabler {};
  42 +}
  43 +constexpr detail::enabler dummy = {};
  44 +
  45 +template <typename Condition>
  46 +using EnableIf = typename std::enable_if<Condition::value, detail::enabler>::type;
  47 +template <typename Condition>
  48 +using DisableIf = typename std::enable_if<!Condition::value, detail::enabler>::type;
  49 +
  50 +
39 51 struct Combiner {
40 52 int num;
41 53 bool positional;
... ... @@ -252,9 +264,8 @@ public:
252 264 };
253 265  
254 266  
255   -template<typename T>
256   -typename std::enable_if<std::is_integral<T>::value, bool>::type
257   -lexical_cast(std::string input, T& output) {
  267 +template<typename T, EnableIf<std::is_integral<T>> = dummy>
  268 +bool lexical_cast(std::string input, T& output) {
258 269 logit("Int lexical cast " + input);
259 270 try{
260 271 output = (T) std::stoll(input);
... ... @@ -266,9 +277,8 @@ lexical_cast(std::string input, T&amp; output) {
266 277 }
267 278 }
268 279  
269   -template<typename T>
270   -typename std::enable_if<std::is_floating_point<T>::value, bool>::type
271   -lexical_cast(std::string input, T& output) {
  280 +template<typename T, EnableIf<std::is_floating_point<T>> = dummy>
  281 +bool lexical_cast(std::string input, T& output) {
272 282 logit("Floating lexical cast " + input);
273 283 try{
274 284 output = (T) std::stold(input);
... ... @@ -281,11 +291,9 @@ lexical_cast(std::string input, T&amp; output) {
281 291 }
282 292  
283 293 // String and similar
284   -template<typename T>
285   -typename std::enable_if<
286   - !std::is_floating_point<T>::value
287   - && !std::is_integral<T>::value, bool>::type
288   -lexical_cast(std::string input, T& output) {
  294 +template<typename T,
  295 +typename std::enable_if<!std::is_floating_point<T>::value && !std::is_integral<T>::value, detail::enabler>::type = dummy>
  296 +bool lexical_cast(std::string input, T& output) {
289 297 logit("Direct lexical cast: " + input);
290 298 output = input;
291 299 return true;
... ... @@ -375,9 +383,8 @@ public:
375 383 }
376 384  
377 385 /// Add option for string
378   - template<typename T>
379   - typename std::enable_if<!std::is_array<T>::value, void>::type
380   - add_option(
  386 + template<typename T, DisableIf<std::is_array<T>> = dummy>
  387 + void add_option(
381 388 std::string name, ///< The name, long,short
382 389 T &variable, ///< The variable to set
383 390 std::string discription="", ///< Discription string
... ... @@ -440,11 +447,10 @@ public:
440 447 }
441 448  
442 449 /// Add option for flag
443   - template<typename T>
444   - typename std::enable_if<std::is_integral<T>::value, void>::type
445   - add_flag(
  450 + template<typename T, EnableIf<std::is_integral<T>> = dummy>
  451 + void add_flag(
446 452 std::string name, ///< The name, short,long
447   - T &count, ///< A varaible holding the count
  453 + T &count, ///< A varaible holding the count
448 454 std::string discription="" ///< Discription string
449 455 ) {
450 456  
... ...