iofortstr.h

#pragma once
#include <cstring>
#include <string>
 
namespace tinker {
class FortranStringView
{
private:
   char* const m_b; // begin in [begin, end)
   char* const m_e; // end in [begin, end)
 
   FortranStringView() = delete; // no default constructor
 
   // If `dst != src`, copy the `first_n` characters from `src` to `dst`;
   // fill `dst` with blanks if `first_n` is less than `dstlen`;
   // `dst` is NOT NULL-terminated.
   static void copyWithBlank(char* dst, size_t dstlen, const char* src,
      size_t first_n);
 
   // Compare to a string `src` of `len`.
   // The shorter string is filled by blanks prior to comparison.
   bool ifEq(const char* src, size_t len) const;
 
   // Returns the max number of characters in the string
   // including the trailing whitespaces.
   size_t size() const;
 
public:
   template <size_t Len>
   FortranStringView(char (&src)[Len])
      : m_b(src)
      , m_e(m_b + Len)
   {}
   FortranStringView(char* src, size_t len);
 
   template <size_t Len>
   FortranStringView& operator=(const char (&src)[Len])
   {
      copyWithBlank(m_b, size(), src, Len);
      return *this;
   }
   FortranStringView& operator=(const char* src);
   FortranStringView& operator=(const std::string& src);
 
   template <size_t Len>
   bool operator==(const char (&src)[Len]) const
   {
      return ifEq(src, Len);
   }
   bool operator==(const char* src) const;
   bool operator==(const std::string& src) const;
   bool operator==(const FortranStringView& src) const;
 
   size_t len_trim() const;
 
   std::string trim() const;
 
   FortranStringView operator()(int begin1, int back1) const;
 
   FortranStringView operator()(int begin1) const;
};
 
using FstrView = FortranStringView;
}