Remove null_terminated_array C++ bits

These are now unused.

CMakeLists.txt

@@ -121,7 +121,6 @@ set(FISH_SRCS
     src/highlight.cpp
     src/input_common.cpp
     src/input.cpp
-    src/null_terminated_array.cpp
     src/output.cpp
     src/pager.cpp
     src/parse_util.cpp

src/fish_tests.cpp

@@ -80,7 +80,6 @@
 #include "kill.rs.h"
 #include "lru.h"
 #include "maybe.h"
-#include "null_terminated_array.h"
 #include "operation_context.h"
 #include "pager.h"
 #include "parse_constants.h"

src/null_terminated_array.cpp

@@ -1,19 +0,0 @@
-#include "null_terminated_array.h"
-
-std::vector<std::string> wide_string_list_to_narrow(const std::vector<wcstring> &strs) {
-    std::vector<std::string> res;
-    res.reserve(strs.size());
-    for (const wcstring &s : strs) {
-        res.push_back(wcs2zstring(s));
-    }
-    return res;
-}
-
-const char **owning_null_terminated_array_t::get() { return impl_->get(); }
-
-owning_null_terminated_array_t::owning_null_terminated_array_t(std::vector<std::string> &&strings)
-    : impl_(new_owning_null_terminated_array(strings)) {}
-
-owning_null_terminated_array_t::owning_null_terminated_array_t(
-    rust::Box<OwningNullTerminatedArrayRefFFI> impl)
-    : impl_(std::move(impl)) {}

src/null_terminated_array.h

@@ -1,83 +0,0 @@
-// Support for null-terminated arrays like char**.
-#ifndef FISH_NULL_TERMINATED_ARRAY_H
-#define FISH_NULL_TERMINATED_ARRAY_H
-
-#include "config.h"  // IWYU pragma: keep
-
-#include <cstddef>
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "common.h"
-#include "cxx.h"
-
-struct OwningNullTerminatedArrayRefFFI;
-#if INCLUDE_RUST_HEADERS
-#include "null_terminated_array.rs.h"
-#endif
-
-/// This supports the null-terminated array of NUL-terminated strings consumed by exec.
-/// Given a list of strings, construct a vector of pointers to those strings contents.
-/// This is used for building null-terminated arrays of null-terminated strings.
-/// *Important*: the vector stores pointers into the interior of the input strings, which may be
-/// subject to the small-string optimization. This means that pointers will be left dangling if any
-/// input string is deallocated *or moved*. This class should only be used in transient calls.
-template <typename T>
-class null_terminated_array_t : noncopyable_t, nonmovable_t {
-   public:
-    /// \return the list of pointers, appropriate for envp or argv.
-    /// Note this returns a mutable array of const strings. The caller may rearrange the strings but
-    /// not modify their contents.
-    const T **get() {
-        assert(!pointers_.empty() && pointers_.back() == nullptr && "Should have null terminator");
-        return &pointers_[0];
-    }
-
-    // Construct from a list of strings (std::string or wcstring).
-    // This holds pointers into the strings.
-    explicit null_terminated_array_t(const std::vector<std::basic_string<T>> &strs) {
-        pointers_.reserve(strs.size() + 1);
-        for (const auto &s : strs) {
-            pointers_.push_back(s.c_str());
-        }
-        pointers_.push_back(nullptr);
-    }
-
-   private:
-    std::vector<const T *> pointers_{};
-};
-
-/// A container which exposes a null-terminated array of pointers to strings that it owns.
-/// This is useful for persisted null-terminated arrays, e.g. the exported environment variable
-/// list. This assumes char, since we don't need this for wchar_t.
-/// Note this class is not movable or copyable as it embeds a null_terminated_array_t.
-struct owning_null_terminated_array_t {
-   public:
-    // Access the null-terminated array of nul-terminated strings, appropriate for execv().
-    const char **get();
-
-    // Construct, taking ownership of a list of strings.
-    explicit owning_null_terminated_array_t(std::vector<std::string> &&strings);
-
-    // Construct from the FFI side.
-    explicit owning_null_terminated_array_t(rust::Box<OwningNullTerminatedArrayRefFFI> impl);
-
-   private:
-    const rust::Box<OwningNullTerminatedArrayRefFFI> impl_;
-};
-
-/// Helper to convert a list of wcstring to a list of std::string.
-std::vector<std::string> wide_string_list_to_narrow(const std::vector<wcstring> &strs);
-
-/// \return the length of a null-terminated array of pointers to something.
-template <typename T>
-size_t null_terminated_array_length(const T *const *arr) {
-    size_t idx = 0;
-    while (arr[idx] != nullptr) {
-        idx++;
-    }
-    return idx;
-}
-
-#endif  // FISH_NULL_TERMINATED_ARRAY_H