Remove stringref::c_str()

The expected semantics of c_str() (a null-terminated string) cannot
be satisfied with a string reference, so remove the function entirely
to prevent people from using it in buggy ways.

Replaces c_str() with data() in places where it is presumed safe,
otherwise constructs temporary string instances. Certain callsites
have been de-stringref'd in favor of regular strings, in particular
where C APIs have been transitively called. The vast majority of
these were called with string parameters anyway, so should not
cause much extra allocation.

2 files changed, 2 insertions, 2 deletions

diff --git a/eval/src/vespa/eval/tensor/dense/dense_tensor_view.cpp b/eval/src/vespa/eval/tensor/dense/dense_tensor_view.cpp
index 80548d33e72..f2ddcb38698 100644
--- a/eval/src/vespa/eval/tensor/dense/dense_tensor_view.cpp
+++ b/eval/src/vespa/eval/tensor/dense/dense_tensor_view.cpp
@@ -67,7 +67,7 @@ checkDimensions(const DenseTensorView &lhs, const DenseTensorView &rhs,
                                                 "dense tensor %s, "
                                                 "lhs dimensions = '%s', "
                                                 "rhs dimensions = '%s'",
-                                                operation.c_str(),
+                                                operation.data(),
                                                 dimensionsAsString(lhs.fast_type()).c_str(),
                                                 dimensionsAsString(rhs.fast_type()).c_str()));
     }
diff --git a/eval/src/vespa/eval/tensor/sparse/sparse_tensor_unsorted_address_builder.h b/eval/src/vespa/eval/tensor/sparse/sparse_tensor_unsorted_address_builder.h
index 681bdabc5eb..7e69adb5804 100644
--- a/eval/src/vespa/eval/tensor/sparse/sparse_tensor_unsorted_address_builder.h
+++ b/eval/src/vespa/eval/tensor/sparse/sparse_tensor_unsorted_address_builder.h
@@ -53,7 +53,7 @@ class SparseTensorUnsortedAddressBuilder
     ElementStringRef
     append(vespalib::stringref str)
     {
-        const char *cstr = str.c_str();
+        const char *cstr = str.data();
         uint32_t start = _elementStrings.size();
         _elementStrings.insert(_elementStrings.end(),
                                cstr, cstr + str.size() + 1);